Split stability tests into a separate Github Actions workflow

[mustafain117]

Description:

Added a separate workflow for Stability tests
Note: this new workflow runs make stability-tests, and the makefile currently has the the stability-tests as disabled:

.PHONY: stability-tests
stability-tests: otelcontribcol
	@echo Stability tests are disabled until we have a stable performance environment.
	@echo To enable the tests replace this echo by $(MAKE) -C testbed run-stability-tests

As a result, the new workflow will run a noop make target until the tests are enabled (This new workflow can be disabled until then)
Link to tracking Issue:
resolves #4045