feat: use FTL_ENDPOINT for ftl-generator #308

Job	Run time
Release Go Binaries	4m 26s
Release Go Binaries	4m 26s
Release JARs	7m 19s
Release JARs	7m 19s
Build Controller Docker Image	4m 12s
Build Controller Docker Image	3m 44s
Build Runner Docker Image	3m 49s
Build Runner Docker Image	3m 49s
Release Assets	9s
Release Assets	5s
Release Hermit	4s
Release Hermit	4s
	39m 26s

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