Update Envoy to 6269243 (Dec 11th, 2023)

[qqustc]

• change context.runtime() to context.serverFactoryContext().runtime() in source/server/http_dynamic_delay_filter_config.cc due to factory context: refactored factory context envoy#31189 and implemented PANIC methods in NighthawkServerFactoryContext
• replace @envoy//source/exe:envoy_common_lib_with_external_headers with @envoy//source/exe:all_extensions_lib_with_external_headers due to exe: build cleanup envoy#31109
• replace @envoy//source/exe:main_common_lib_with_external_headers with @envoy//source/exe:main_common_with_all_extensions_lib_with_external_headers due to a combination of options: splitting into base class and command line parsing envoy#30924 and exe: build cleanup envoy#31109 causing unit test UtilityAddressResolutionTest, AddressResolution failed because envoy.network.dns_resolver.cares was not linked in
• lower upstream_cx_rx_bytes_total counter threshold in test_http_h2 integration test.
• disable oghttp2 in Nighthawk which was enabled by default in Envoy in envoyproxy/envoy@b58d312
• sync files

[eric846]

/retest

[qqustc]

/retest