feat: add validate-policy-bot-action (#497)

* feat: add validate-policy-bot-action

* add poly-bot rules

* update description

* remove policy bot config validation for this repo

* update action readme

* add inputs docs to the readme

actions/validate-policy-bot-config/README.md

@@ -0,0 +1,29 @@
+# validate-policy-bot-config
+
+Validates the `.policy.yml` configuration file for [Policy Bot](https://github.com/palantir/policy-bot).
+See [https://github.com/palantir/policy-bot?tab=readme-ov-file#configuration](Policy Bots' documentation) for more informations.
+
+## Inputs
+
+- `validation_endpoint`: The endpoint to validate the configuration against. Defaults to `https://policy-bot.grafana.net/api/v1/validate`.
+
+Example workflow:
+
+```yaml
+name: validate-policy-bot
+on:
+  pull_request:
+    paths:
+      - ".policy.yml"
+  push:
+    paths:
+      - ".policy.yml
+jobs:
+  validate-policy-bot:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Validate Policy Bot configuration
+        uses: grafana/shared-workflows/actions/validate-policy-bot-config@main
+```

actions/validate-policy-bot-config/action.yml

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+name: Validate Policy Bot Config
+description: Validates the Policy Bot configuration file.
+
+inputs:
+  validation_endpoint:
+    description: |
+      Validation API endpoint.
+    default: https://github-policy-bot.grafana-ops.net/api/validate
+
+runs:
+  using: composite
+  steps:
+    - name: Validate Policy Bot config
+      shell: bash
+      run: |
+        curl \
+          --silent \
+          --fail-with-body \
+          --request PUT \
+          --upload-file .policy.yml \
+          ${{ inputs.validation_endpoint }}