ci: Automate milestone closing & commenting (#627)

.github/workflows/milestone-closed.yml

@@ -0,0 +1,22 @@
+name: Closed Milestones
+
+on:
+  milestone:
+    types: [closed]
+
+permissions:
+  issues: write
+  pull-requests: write
+
+jobs:
+  Comment:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: bflad/action-milestone-comment@v1
+        with:
+          body: |
+            This functionality has been released in [${{ github.event.milestone.title }} of the language server](https://github.com/${{ github.repository }}/blob/${{ github.event.milestone.title }}/CHANGELOG.md).
+            If you use the official Terraform VS Code extension, it will prompt you to upgrade to this version automatically upon next launch or within the next 24 hours.
+
+            For further feature requests or bug reports with this functionality, please create a [new GitHub issue](https://github.com/${{ github.repository }}/issues/new/choose) following the template. Thank you!

.github/workflows/release.yml

@@ -7,6 +7,7 @@ on:
 
 permissions:
   contents: write
+  issues: write
 
 env:
   GOPROXY: https://proxy.golang.org/

.goreleaser.yml

@@ -118,5 +118,9 @@ publishers:
       - AWS_SESSION_TOKEN={{ .Env.AWS_SESSION_TOKEN }}
     cmd: hc-releases upload-file {{ abs .ArtifactPath }}
 
+milestones:
+  - name_template: "{{ .Tag }}"
+    close: true
+
 changelog:
   skip: true