CI: Update GHA recipes

.github/dependabot.yml

@@ -0,0 +1,20 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+
+  # Check GitHub Actions
+  # Workflow files stored in the default location of `.github/workflows`
+  - directory: "/"
+    package-ecosystem: "github-actions"
+    schedule:
+      interval: "monthly"
+
+  # Python dependencies.
+  - directory: "/"
+    package-ecosystem: "pip"
+    schedule:
+      interval: "weekly"

.github/workflows/platformio-ci.yaml

@@ -1,10 +1,10 @@
 name: PlatformIO CI
 
 on:
-  push:
-    branches: [ master ]
   pull_request:
-    branches: [ master ]
+    branches: ~
+  push:
+    branches: [ main ]
 
 jobs:
   build:
@@ -13,24 +13,26 @@ jobs:
 
     steps:
       - name: Acquire sources
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Cache pip
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: ~/.cache/pip
           key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
           restore-keys: |
             ${{ runner.os }}-pip-
 
       - name: Cache PlatformIO
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: ~/.platformio
           key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
 
       - name: Setup Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
 
       - name: Install PlatformIO
         run: |