Update main.yml integration tests to use swift_test_matrix #70

Job	Run time
Construct Examples matrix	2s
Cxx interop / Construct Cxx interop matrix	4s
Unit tests / Construct unit test matrix	3s
HTTP/2 spec tests / Linux (5.9)	1m 17s
HTTP/2 spec tests / Linux (5.10)	1m 13s
HTTP/2 spec tests / Linux (6.0)	1m 40s
HTTP/2 spec tests / Linux (nightly-6.1)	1m 49s
HTTP/2 spec tests / Linux (nightly-main)	1m 52s
HTTP/2 spec tests / Windows (6.0)	1s
HTTP/2 spec tests / Windows (nightly-6.1)	3s
HTTP/2 spec tests / Windows (nightly-main)	2s
Soundness / API breakage check	2m 3s
Soundness / Documentation check	1m 43s
Soundness / Unacceptable language check	3s
Soundness / License headers check	6s
Soundness / Broken symlinks check	5s
Soundness / Format check	52s
Soundness / Shell check	33s
Soundness / YAML lint check	4s
Soundness / Python lint check	4s
Integration Tests / Linux (5.9)	3m 18s
Integration Tests / Linux (5.10)	3m 1s
Integration Tests / Linux (6.0)	3m 19s
Integration Tests / Linux (nightly-next)	3m 51s
Integration Tests / Linux (nightly-main)	3m 53s
Unit tests / Unit tests / Linux (5.9)	3m 7s
Unit tests / Unit tests / Linux (5.10)	3m 0s
Unit tests / Unit tests / Linux (6.0)	2m 56s
Unit tests / Unit tests / Linux (nightly-next)	3m 0s
Unit tests / Unit tests / Linux (nightly-main)	2m 58s
Cxx interop / Cxx interop / Linux (5.9)	1m 13s
Cxx interop / Cxx interop / Linux (5.10)	1m 24s
Cxx interop / Cxx interop / Linux (6.0)	1m 24s
Cxx interop / Cxx interop / Linux (nightly-next)	1m 44s
Cxx interop / Cxx interop / Linux (nightly-main)	1m 43s
	53m 30s

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