Fix detection of clang version and v14+ unit tests #2713

Job	Run time
clippy ubuntu-latest	4m 15s
clippy macOS-latest	5m 39s
clippy windows-latest	8m 22s
rustfmt ubuntu-latest	13s
build sccache x86_64-unknown-linux-musl	8m 18s
build sccache-dist x86_64-unknown-linux-musl	6m 18s
build sccache aarch64-unknown-linux-musl	27s
build sccache x86_64-apple-darwin	13m 39s
build sccache aarch64-apple-darwin	13m 27s
build sccache x86_64-pc-windows-msvc	13m 10s
coverage ubuntu-20.04 rust nightly	7m 54s
coverage macOS-11 rust nightly	11m 34s
test ubuntu-20.04 rust 1.65.0	6m 56s
test ubuntu-22.04 rust 1.65.0 dist-server	8m 21s
test ubuntu-20.04 rust stable	4m 7s
test ubuntu-20.04 rust beta	4m 52s
test ubuntu-20.04 rust nightly	5m 12s
test ubuntu-22.04 rust stable	5m 31s
test macOS-11 rust stable	5m 22s
test windows-2019 rust 1.65.0	11m 5s
test windows-2019 rust nightly	6m 52s
test windows-2019 rust beta	7m 37s
test freebsd-13.1 rust stable (macos-12, 13.1)	17m 28s
toml_format	10s
release	0s
	2h 56m 49s

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