Substitue env in header of mcp #5543

Job	Run time
build-and-check	2m 27s
test-integration-packages/billing	1m 8s
test-integration-packages/internal	1m 5s
test-integration-sdk	43s
test-integration-packages/agent-runtime	40s
test-integration-common	42s
test-packages/billing	40s
test-integration-cli	43s
test-packages/internal	46s
test-cli	1m 7s
test-common	42s
test-integration-web	45s
test-.agents	46s
test-sdk	43s
test-web	53s
test-packages/agent-runtime	54s
	14m 44s

Provide feedback