remove .deps file generation

[MartinNowak]

• for development, people can use the much faster std/algorithm.test targets
• for batch unittest recompiling isn't of much interest as all the
  testers just start from a clean slate anyhow
• furthermore the .deps generation is broken anyhow, see Issue 7016

[dlang-bot]

Fix	Bugzilla	Description
✗	7016	local import does not create -deps dependency

[wilzbach]

+3 / -9 🎉

[wilzbach]

CC @RazvanN7 @andralex

[andralex]

I hope @MartinNowak agrees with this... oh wait he wrote the PR!

[RazvanN7]

@andralex maybe you should check this:
dlang/dmd#6748

[wilzbach]

Meh - random failures on FreeBSD again :S

timelimit -t 10 ./generated/freebsd/release/64/unittest_assert  2>&1 1>/dev/null | grep -qF "unittest_assert msg"
diff src-merge.lst.exp ./generated/freebsd/release/64/src-merge.lst
src/rt/util/typeinfo.d(184): Deprecation: identity comparison of static arrays implicitly coerces them to slices, which are compared by reference
src/rt/util/typeinfo.d(184): Deprecation: identity comparison of static arrays implicitly coerces them to slices, which are compared by reference
src/rt/util/typeinfo.d(184): Deprecation: identity comparison of static arrays implicitly coerces them to slices, which are compared by reference
src/rt/util/typeinfo.d(232): Deprecation: identity comparison of static arrays implicitly coerces them to slices, which are compared by reference
src/rt/util/typeinfo.d(232): Deprecation: identity comparison of static arrays implicitly coerces them to slices, which are compared by reference
src/rt/util/typeinfo.d(232): Deprecation: identity comparison of static arrays implicitly coerces them to slices, which are compared by reference
src/rt/util/typeinfo.d(286): Deprecation: identity comparison of static arrays implicitly coerces them to slices, which are compared by reference
gmake[1]: *** [generated/freebsd/release/64/unittest/libdruntime-ut.so] Killed: 9
gmake[1]: *** Waiting for unfinished jobs....
Testing invalid_memory_operation
gmake[2]: Leaving directory `/usr/home/braddr/sandbox/at-client/pull-2540284-FreeBSD_64_64/druntime/test/thread'
timelimit -t 10 ./generated/freebsd/release/64/invalid_memory_operation  2>&1 1>/dev/null | grep -qF "InvalidMemoryOperationError"
Testing unknown_gc
timelimit -t 10 ./generated/freebsd/release/64/unknown_gc  2>&1 1>/dev/null | grep -qF "'unknowngc'"
./generated/freebsd/release/64/merge_true ./generated/freebsd/release/64 
Testing static_dtor
gmake[1]: *** [generated/freebsd/debug/64/unittest/libdruntime-ut.so] Killed: 9
diff src-merge_true.lst.exp ./generated/freebsd/release/64/src-merge_true.lst
! timelimit -t 10 ./generated/freebsd/release/64/static_dtor  2>&1 1>/dev/null | grep -qF "dtor_called_more_than_once"
gmake[1]: *** Waiting for unfinished jobs....