feat!: v4 release (#871)

Any advanced configuration should be done via a
release-please-config.json.

Fixes #859
Fixes #858
Fixes #857
Fixes #852

feat!: remove most configuration options in favor of manifest
configuration to configure the release-please-action
refactor!: rewrite in typescript
feat!: remove command option in favor of setting `release-type` and
`skip-github-release`/`skip-github-pull-request`
feat!: run on node20
deps!: upgrade release-please to v16

.github/workflows/ci.yaml

@@ -9,20 +9,19 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [18, 20]
+        node: [20]
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
         with:
           node-version: ${{ matrix.node }}
-      - run: node --version
       # The first installation step ensures that all of our production
       # dependencies work on the given Node.js version, this helps us find
       # dependencies that don't match our engines field:
       - run: npm install --production --engine-strict --ignore-scripts --no-package-lock
       # Clean up the production install, before installing dev/production:
       - run: rm -rf node_modules
-      - run: npm install
+      - run: npm ci
       - run: npm test
   windows:
     runs-on: windows-latest
@@ -31,13 +30,13 @@ jobs:
       - uses: actions/setup-node@v1
         with:
           node-version: 20
-      - run: npm install
+      - run: npm ci
       - run: npm test
   build-dist:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [18, 20]
+        node: [20]
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1