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/set-env-step-env-override/push.yml

@@ -0,0 +1,24 @@
+on: push
+jobs:
+  _:
+    runs-on: ubuntu-latest
+    env:
+      MY_ENV: test
+    steps:
+    - run: exit 1
+      if: env.MY_ENV != 'test'
+    - run: |
+        runs:
+          using: composite
+          steps:
+          - run: exit 1
+            shell: bash
+            if: env.MY_ENV != 'val'
+          - run: echo "MY_ENV=returnedenv" > $GITHUB_ENV
+            shell: bash
+      shell: cp {0} action.yml
+    - uses: ./
+      env:
+        MY_ENV: val
+    - run: exit 1
+      if: env.MY_ENV != 'returnedenv'