[NFC] Use angle-bracketed includes in public headers #2105

Job	Run time
catalyst	6m 37s
pod-lib-lint (ios, macos-12)	7m 39s
quickstart	11m 8s
quickstart-ftl-cron-only	0s
pod-lib-lint (ios, macos-13)	6m 0s
pod-lib-lint (tvos, macos-12)	6m 46s
pod-lib-lint (tvos, macos-13)	3m 14s
pod-lib-lint (macos --skip-tests, macos-12)	4m 7s
spm (iOS, macos-12)	2m 27s
pod-lib-lint (macos --skip-tests, macos-13)	5m 15s
spm (iOS, macos-13)	3m 34s
pod-lib-lint (watchos, macos-12)	2m 55s
spm (tvOS, macos-12)	2m 19s
pod-lib-lint (watchos, macos-13)	3m 10s
spm (tvOS, macos-13)	4m 0s
spm (macOS, macos-12)	2m 36s
spm (macOS, macos-13)	3m 15s
spm (watchOS, macos-12)	2m 56s
spm (watchOS, macos-13)	3m 56s
spm (catalyst, macos-12)	3m 12s
spm (catalyst, macos-13)	4m 2s
installations-cron-only	0s
	1h 29m 8s

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