ci: Melos publishing from workflow (#3309)

With this PR we'll be able to publish by running an action from the
Actions tab which will create a release PR that we can review and when
that PR is merged it will tag all new packages and trigger release
workflows for them.

.github/workflows/release-prepare.yml

@@ -0,0 +1,26 @@
+name: Prepare release
+on:
+  workflow_dispatch:
+    inputs:
+      prerelease:
+        description: 'Version as prerelease'
+        required: false
+        default: false
+        type: boolean
+
+jobs:
+  prepare-release:
+    name: Prepare release
+    permissions:
+      contents: write
+      pull-requests: write
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: subosito/flutter-action@v2
+      - uses: bluefireteam/melos-action@v3
+        with:
+          run-versioning: ${{ inputs.prerelease == false }}
+          run-versioning-prerelease: ${{ inputs.prerelease == true }}
+          publish-dry-run: true
+          create-pr: true

.github/workflows/release-publish.yml

@@ -0,0 +1,22 @@
+name: Publish packages
+on:
+  # Enable to also publish, when pushing a tag
+  #push:
+  #  tags:
+  #    - '*'
+  workflow_dispatch:
+
+jobs:
+  publish-packages:
+    name: Publish packages
+    permissions:
+      contents: write
+      id-token: write # Required for authentication using OIDC
+    runs-on: [ ubuntu-latest ]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: subosito/flutter-action@v2
+      - uses: bluefireteam/melos-action@v3
+        with:
+          publish: true
+

.github/workflows/release-tag.yml

@@ -0,0 +1,25 @@
+name: Tag release
+on:
+  push:
+    branches: [main]
+
+jobs:
+  publish-packages:
+    name: Create tags for release
+    permissions:
+      contents: write
+    runs-on: [ ubuntu-latest ]
+    if: contains(github.event.head_commit.message, 'chore(release)')
+    steps:
+      - uses: actions/checkout@v4
+      - uses: subosito/flutter-action@v2
+      - uses: bluefireteam/melos-action@v3
+        with:
+          tag: true
+      - run: |
+          melos exec -c1 --no-published --no-private --order-dependents -- \
+          gh workflow run release-publish.yml \
+          --ref \$MELOS_PACKAGE_NAME-v\$MELOS_PACKAGE_VERSION
+          env:
+            GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+