Add CI checks: changelog and cargo publish

.github/workflows/check_changelog.yml

@@ -0,0 +1,20 @@
+name: Check Changelog
+
+on:
+  pull_request:
+    types: [opened, reopened, labeled, unlabeled, synchronize]
+
+permissions:
+  contents: read
+
+jobs:
+  check-changelog:
+    runs-on: ubuntu-latest
+    if: (!contains(github.event.pull_request.labels.*.name, 'skip changelog'))
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Check that CHANGELOG is touched
+        run: |
+          git fetch origin ${{ github.base_ref }} --depth 1 && \
+          git diff remotes/origin/${{ github.base_ref }} --name-only | grep CHANGELOG.md

.github/workflows/ci.yml

@@ -8,6 +8,20 @@ on:
   pull_request:
 
 jobs:
+  check_publishable:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Update Rust toolchain
+        # Most of the time this will be a no-op, since GitHub releases new images every week
+        # which include the latest stable release of Rust, Rustup, Clippy and rustfmt.
+        run: rustup update
+      - name: Rust Cache
+        uses: Swatinem/[email protected]
+      - name: Check cargo publish
+        run: cargo publish --dry-run
+
   lint:
     runs-on: ubuntu-22.04
     steps: