fix(@angular/build): serve extensionless assets without transformation #2747

Job	Run time
build	23s
lint	1m 56s
build-e2e-windows	27s
Browser Compatibility Tests	-1s
test	-1s
publish-snapshots	-1s
e2e-package-managers	0s
e2e	0s
e2e-snapshots	0s
e2e-windows	-1s
	2m 42s

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