$GITHUB_PATH support (#566)

* Regression in the .golangci.yml file

* This looks like an even better fix to #451

The previous solution only prevented the `starting container process caused "exec: \"bash\"`
error when someone added an "extra" path in the workflow using `::add-path`

* Add support for >> $GITHUB_PATH

* The newRunCommand has too high cyclomatic complexity

* Add "linux/arm64" to new test

* The cyclop linter was complaining so I extracted some funcs

* Close some readers

* Fix typo

* fix: add missing composite function

* Fix regress from merging

* Keep the error messages as is

* consolidate with master

* Close the tar reader on defer

* New way to get ContainerWorkdir

* Remove arch from runner test

* Separate the UpdateFromEnv and UpdateFromPath

Co-authored-by: hackercat <me@hackerc.at>

pkg/runner/testdata/env-and-path/push.yaml

@@ -0,0 +1,41 @@
+name: env-and-path
+on: push
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: "Append to $GITHUB_PATH"
+        run: |
+          echo "$HOME/someFolder" >> $GITHUB_PATH
+      - name: "Append some more to $GITHUB_PATH"
+        run: |
+          echo "$HOME/someOtherFolder" >> $GITHUB_PATH
+      - name: "Check PATH"
+        run: |
+          if [[ ! "${PATH}" =~ .*"$HOME/"someFolder.*"$HOME/"someOtherFolder ]]; then
+            echo "${PATH} doesn't match .*someFolder.*someOtherFolder"
+            exit 1
+          fi
+      - name: "Write single line env to $GITHUB_ENV"
+        run: |
+          echo "KEY=value" >> $GITHUB_ENV
+      - name: "Check single line env"
+        run: |
+          if [[ "${KEY}" != "value" ]]; then
+            echo "${KEY} dosen't == 'value'"
+            exit 1
+          fi
+      - name: "Write multiline env to $GITHUB_ENV"
+        run: |
+          echo 'KEY2<<EOF' >> $GITHUB_ENV
+                echo value2 >> $GITHUB_ENV
+                echo 'EOF' >> $GITHUB_ENV
+      - name: "Check multiline line env"
+        run: |
+          if [[ "${KEY2}" != "value2" ]]; then
+            echo "${KEY2} dosen't == 'value'"
+            exit 1
+          fi
+
+