Use Cassandra service for unit tests #16

Job	Run time
Unit tests / Unit tests (swift:5.9-jammy, 5.9, false)	26s
Unit tests / Unit tests (swift:5.10-jammy, 5.10, true)	2m 59s
Unit tests / Unit tests (swift:6.0-jammy, 6.0, false)	31s
Unit tests / Unit tests (swiftlang/swift:nightly-6.0-jammy, nightly-6.0, false)	36s
Unit tests / Unit tests (swiftlang/swift:nightly-main-jammy, nightly-main, false)	37s
Soundness / API breakage check	0s
Soundness / Documentation check	3m 10s
Soundness / Unacceptable language check	10s
Soundness / Broken symlinks check	10s
Soundness / Format check	33s
Soundness / License headers check	5s
Soundness / Python lint check	6s
Soundness / YAML lint check	11s
Soundness / Shell check	35s
Cxx interop / Cxx interop / Windows (6.0)	3s
Cxx interop / Cxx interop / Linux (5.9)	2m 45s
Cxx interop / Cxx interop / Windows (nightly-6.0)	3s
Cxx interop / Cxx interop / Linux (5.10)	2m 43s
Cxx interop / Cxx interop / Windows (nightly-main)	1s
Cxx interop / Cxx interop / Linux (6.0)	3m 4s
Cxx interop / Cxx interop / Linux (nightly-6.0)	3m 37s
Cxx interop / Cxx interop / Linux (nightly-main)	3m 47s
	26m 12s

Provide feedback