Support .in Dockerfiles via cpp when available #4156

Job	Run time
Install Script (ubuntu-latest)	26s
Install Script (macos-latest)	38s
OCI Implementation Registry Compatibility	1m 6s
CLI	42s
Tests Matrix (src/test/cli.exec.buildKit.2.test.ts)	6m 28s
Tests Matrix (src/test/container-features/featuresCLICommands.test.ts)	2m 52s
Tests Matrix (src/test/cli.exec.buildKit.1.test.ts)	6m 13s
Tests Matrix (src/test/cli.build.test.ts)	11m 36s
Tests Matrix (src/test/container-features/containerFeaturesOCIPush.test.ts)	1m 53s
Tests Matrix (src/test/container-features/e2e.test.ts)	3m 48s
Tests Matrix (src/test/container-features/containerFeaturesOrder.test.ts)	54s
Tests Matrix (src/test/cli.test.ts)	58s
Tests Matrix (src/test/imageMetadata.test.ts)	7m 58s
Tests Matrix (src/test/cli.podman.test.ts)	2m 30s
Tests Matrix (src/test/cli.exec.nonBuildKit.2.test.ts)	5m 0s
Tests Matrix (src/test/cli.exec.nonBuildKit.1.test.ts)	5m 7s
Tests Matrix (src/test/cli.up.test.ts)	5m 16s
Tests Matrix (--exclude src/test/container-features/containerFeaturesOrder.test.ts --exclude src/...	16m 20s
Tests	4s
	1h 19m 49s

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