Only apply standard swift settings on valid targets #114

Job	Run time
Unit tests / Construct unit test matrix	5s
Integration test / Linux (5.9)	1m 45s
Integration test / Linux (5.10)	1m 46s
Integration test / Linux (6.0)	1m 50s
Integration test / Linux (nightly-6.1)	2m 14s
Integration test / Linux (nightly-main)	33s
Integration test / Windows (6.0)	2s
Integration test / Windows (nightly-6.1)	1s
Integration test / Windows (nightly-main)	3s
Soundness / API breakage check	58s
Soundness / Documentation check	1m 8s
Soundness / Unacceptable language check	2s
Soundness / License headers check	5s
Soundness / Broken symlinks check	3s
Soundness / Format check	36s
Soundness / Shell check	30s
Soundness / YAML lint check	3s
Soundness / Python lint check	5s
Unit tests / Unit tests / Linux (5.9)	39s
Unit tests / Unit tests / Linux (5.10)	41s
Unit tests / Unit tests / Linux (6.0)	54s
Unit tests / Unit tests / Linux (nightly-next)	1m 0s
Unit tests / Unit tests / Linux (nightly-main)	1m 1s
	16m 4s

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