refactor: GITHUB_ENV command / remove env.PATH (#1503)

* fix: GITHUB_ENV / PATH handling

* apply workaround

* add ctx to ApplyExtraPath

* fix: Do not leak step env in composite

See https://github.com/nektos/act/pull/1585 for a test

* add more tests

---------

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

pkg/runner/step_test.go

@@ -148,9 +148,6 @@ func TestSetupEnv(t *testing.T) {
 	sm.On("getStepModel").Return(step)
 	sm.On("getEnv").Return(&env)
 
-	cm.On("UpdateFromImageEnv", &env).Return(func(ctx context.Context) error { return nil })
-	cm.On("UpdateFromEnv", "/var/run/act/workflow/envs.txt", &env).Return(func(ctx context.Context) error { return nil })
-
 	err := setupEnv(context.Background(), sm)
 	assert.Nil(t, err)
 
@@ -174,7 +171,6 @@ func TestSetupEnv(t *testing.T) {
 		"GITHUB_ACTION_REPOSITORY": "",
 		"GITHUB_API_URL":           "https:///api/v3",
 		"GITHUB_BASE_REF":          "",
-		"GITHUB_ENV":               "/var/run/act/workflow/envs.txt",
 		"GITHUB_EVENT_NAME":        "",
 		"GITHUB_EVENT_PATH":        "/var/run/act/workflow/event.json",
 		"GITHUB_GRAPHQL_URL":       "https:///api/graphql",