ci: switch to actions (#234)

- closes #89

Reviewed-on: https://codeberg.org/forgejo-contrib/forgejo-helm/pulls/234
Co-authored-by: Michael Kriese <michael.kriese@visualon.de>
Co-committed-by: Michael Kriese <michael.kriese@visualon.de>

.forgejo/actions/setup-node/action.yml

@@ -0,0 +1,13 @@
+# action.yml
+name: setup-node
+description: 'setup node'
+
+runs:
+  using: 'composite'
+  steps:
+    - uses: actions/setup-node@v4
+      with:
+        node-version-file: .node-version
+        cache: 'npm'
+    - shell: bash
+      run: npm ci