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/testdata/do-not-leak-step-env-in-composite/push.yml

@@ -8,6 +8,7 @@ jobs:
           using: composite
           steps:
           - run: exit 1
+            shell: bash
             if: env.LEAK_ENV != 'val'
       shell: cp {0} action.yml
     - uses: ./