fix: crash malformed composite action (#1616)

* fix: crash malformed composite action

* Add remote composite action test

---------

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

pkg/runner/testdata/no-panic-on-invalid-composite-action/push.yml

@@ -0,0 +1,29 @@
+on: push
+jobs:
+  local-invalid-step:
+    runs-on: ubuntu-latest
+    steps:
+    - run: |
+        runs:
+          using: composite
+          steps:
+          - name: Foo
+          - uses: Foo/Bar
+      shell: cp {0} action.yml
+    - uses: ./
+  local-missing-steps:
+    runs-on: ubuntu-latest
+    steps:
+    - run: |
+        runs:
+          using: composite
+      shell: cp {0} action.yml
+    - uses: ./
+  remote-invalid-step:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: nektos/act-test-actions/invalid-composite-action/invalid-step@main
+  remote-missing-steps:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: nektos/act-test-actions/invalid-composite-action/missing-steps@main