[refactor] Clean up env vars

[ianlewis]

Env vars need to be cleaned up in the container workflow. Many env vars set here are legacy vars that are no longer used.

slsa-github-generator/.github/workflows/generator_container_slsa3.yml

Lines 19 to 30 in 1a55da8

	BUILDER_BINARY: generic-generator
	BUILDER_RELEASE_BINARY: slsa-generator-generic-linux-amd64
	BUILDER_REPOSITORY: slsa-framework/slsa-github-generator
	# Verifier
	# NOTE: These VERIFIER_* variables are used for verification of generator
	# release binaries when the compile-generator input is false.
	VERIFIER_REPOSITORY: slsa-framework/slsa-verifier
	VERIFIER_RELEASE_BINARY: slsa-verifier-linux-amd64
	VERIFIER_RELEASE_BINARY_SHA256: f92fc4e571949c796d7709bb3f0814a733124b0155e484fad095b5ca68b4cb21
	VERIFIER_RELEASE: v1.1.1
	# Builder location
	BUILDER_DIR: internal/builders