Add include test for legacy provider #73

Job	Run time
basic_clang	7m 32s
basic_gcc	8m 52s
check_docs	1m 11s
check_update	3m 13s
check-ansi	5m 30s
minimal	4m 18s
no-deprecated	9m 23s
no-shared (ubuntu-latest)	6m 50s
address_ub_sanitizer	14m 35s
no-shared (macos-latest)	8m 59s
enable_non-default_options	8m 3s
fips_and_ktls	7m 54s
memory_sanitizer	18m 57s
non-caching	23m 19s
threads_sanitizer	7m 26s
enable_brotli_and_asan_ubsan	14m 22s
buildtest	11m 52s
enable_brotli_and_zstd_dynamic	8m 55s
enable_brotli_dynamic	8m 42s
enable_zstd_and_asan_ubsan	16m 5s
enable_zstd_dynamic	7m 23s
enable-tfo (ubuntu-latest)	10m 2s
legacy	6m 10s
enable-tfo (macos-latest)	9m 46s
no-legacy	7m 56s
out-of-source-and-install (ubuntu-latest)	9m 36s
out-of-source-and-install (macos-latest)	16m 21s
external-test-cf-quiche	7m 39s
external-test-pyca (1.51.0, 3.9)	14m 14s
external-tests	17m 8s
	5h 2m 13s

Provide feedback