Revert "Prepare: run E2E smoketests with GitHub actions (#23301)" (#23553)

This reverts commit 68be3a6bcd.

e2e-tests/Makefile

@@ -1,28 +0,0 @@
-.PHONY: all run stop
-all: run
-run: start-server prepare-server run-cypress
-stop: stop-server stop-dashboard clean-env-placeholders
-
-.PHONY: start-server prepare-server run-cypress stop-server restart-server
-start-server:
-	./.ci/server.start.sh
-prepare-server:
-	./.ci/server.prepare.sh
-run-cypress:
-	./.ci/server.run_cypress.sh
-stop-server:
-	./.ci/server.stop.sh
-restart-server: stop-server start-server
-
-.PHONY: start-dashboard stop-dashboard
-start-dashboard:
-	./.ci/dashboard.start.sh
-stop-dashboard:
-	./.ci/dashboard.stop.sh
-
-.PHONY: print-env-placeholders clean-env-placeholders
-print-env-placeholders:
-	find .ci -maxdepth 1 -name '.env.*'  | xargs --verbose -l cat
-clean-env-placeholders:
-	git reset .ci/.env.*
-	git checkout .ci/.env.*