[Fix](streamingjob) modify select backend policy for streaming job

[JNSimba]

What problem does this PR solve?

Issue Number: close #xxx

Related PR: #58898

Problem Summary:

Modify select backend policy for streaming job

None

Check List (For Author)

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[Thearas]

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR.

Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[JNSimba]

run buildall

[JNSimba]

run buildall

[doris-robot]

TPC-H: Total hot run time: 31964 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpch-tools
Tpch sf100 test result on commit 6351675b2ad77db10fd5733752ce1859e8450db5, data reload: false

------ Round 1 ----------------------------------
q1	17620	4181	4103	4103
q2	2029	386	261	261
q3	10100	1290	732	732
q4	10222	888	315	315
q5	7569	2067	1794	1794
q6	190	176	139	139
q7	947	806	670	670
q8	9256	1367	1094	1094
q9	4865	4570	4548	4548
q10	6817	1785	1397	1397
q11	534	304	280	280
q12	679	710	603	603
q13	17795	3860	3162	3162
q14	287	289	272	272
q15	601	525	505	505
q16	691	678	619	619
q17	670	768	533	533
q18	6581	6376	6661	6376
q19	1119	1079	661	661
q20	420	391	287	287
q21	3173	2618	2663	2618
q22	1096	1064	995	995
Total cold run time: 103261 ms
Total hot run time: 31964 ms

----- Round 2, with runtime_filter_mode=off -----
q1	4354	4288	4261	4261
q2	343	416	305	305
q3	2212	2737	2396	2396
q4	1457	1942	1439	1439
q5	4612	4659	4234	4234
q6	215	173	130	130
q7	2017	1939	1717	1717
q8	2567	2344	2365	2344
q9	7113	7114	7118	7114
q10	2423	2727	2316	2316
q11	554	481	446	446
q12	747	774	585	585
q13	3383	3838	3102	3102
q14	264	277	257	257
q15	525	496	498	496
q16	620	655	629	629
q17	1104	1208	1281	1208
q18	7476	7358	7079	7079
q19	842	765	791	765
q20	1927	2001	1782	1782
q21	4549	4364	4321	4321
q22	1066	1038	1020	1020
Total cold run time: 50370 ms
Total hot run time: 47946 ms

[doris-robot]

TPC-DS: Total hot run time: 173368 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpcds-tools
TPC-DS sf100 test result on commit 6351675b2ad77db10fd5733752ce1859e8450db5, data reload: false

query5	4841	591	438	438
query6	330	230	210	210
query7	4216	473	261	261
query8	347	254	243	243
query9	8761	2668	2647	2647
query10	541	370	320	320
query11	15331	15169	14869	14869
query12	176	117	114	114
query13	1267	500	378	378
query14	6433	3006	2976	2976
query14_1	2606	2603	2639	2603
query15	203	188	177	177
query16	989	485	447	447
query17	1081	642	551	551
query18	2564	434	331	331
query19	220	213	207	207
query20	129	118	114	114
query21	220	140	117	117
query22	3950	3861	3894	3861
query23	16007	15421	15603	15421
query23_1	15411	15342	15339	15339
query24	7388	1558	1191	1191
query24_1	1212	1179	1202	1179
query25	576	476	432	432
query26	1246	272	164	164
query27	2755	453	290	290
query28	4570	2140	2128	2128
query29	834	557	466	466
query30	308	242	215	215
query31	811	633	540	540
query32	79	74	67	67
query33	554	352	298	298
query34	885	929	522	522
query35	738	763	686	686
query36	826	877	817	817
query37	136	101	79	79
query38	2734	2812	2710	2710
query39	768	776	739	739
query39_1	721	721	704	704
query40	221	138	123	123
query41	77	67	70	67
query42	113	103	106	103
query43	439	461	443	443
query44	1367	738	719	719
query45	187	188	181	181
query46	845	948	595	595
query47	1411	1460	1326	1326
query48	322	328	253	253
query49	631	426	340	340
query50	649	287	213	213
query51	3751	3807	3743	3743
query52	115	111	106	106
query53	295	338	280	280
query54	312	270	264	264
query55	81	78	74	74
query56	300	307	312	307
query57	1015	1006	948	948
query58	286	260	258	258
query59	2087	2232	2174	2174
query60	335	324	315	315
query61	226	154	153	153
query62	402	358	325	325
query63	298	264	267	264
query64	5018	1313	989	989
query65	3818	3750	3728	3728
query66	1404	430	305	305
query67	15433	15088	14984	14984
query68	6896	989	711	711
query69	504	342	313	313
query70	1023	914	891	891
query71	362	299	276	276
query72	5988	3452	3497	3452
query73	766	714	312	312
query74	8853	8889	8596	8596
query75	2857	2781	2450	2450
query76	3771	1066	637	637
query77	518	380	285	285
query78	9563	9768	9108	9108
query79	1248	920	590	590
query80	607	581	485	485
query81	518	268	234	234
query82	209	140	111	111
query83	253	260	234	234
query84	260	124	104	104
query85	902	528	469	469
query86	402	321	310	310
query87	2850	2936	2789	2789
query88	3146	2237	2192	2192
query89	402	347	319	319
query90	2186	159	157	157
query91	186	165	138	138
query92	94	70	58	58
query93	1161	909	533	533
query94	567	315	286	286
query95	575	383	296	296
query96	589	457	204	204
query97	2321	2391	2328	2328
query98	226	204	199	199
query99	580	591	491	491
Total cold run time: 253569 ms
Total hot run time: 173368 ms

[JNSimba]

run cloud_p0

[sollhui]

LGTM

[github-actions]

PR approved by anyone and no changes requested.

[liaoxin01]

LGTM

[github-actions]

PR approved by at least one committer and no changes requested.