Test both ubuntu's builtin and the PPA's 8.3

.github/workflows/php.yml

@@ -1,4 +1,4 @@
-name: PHP Composer install tests
+name: PHP Composer install tests - Ubuntu builtin PHP
 
 on:
   push:

.github/workflows/php83.yml

@@ -0,0 +1,67 @@
+name: PHP Composer install tests - Ubuntu PPA PHP 8.3
+
+on:
+  push:
+    branches: [ "FRAMEWORK_6_0" ]
+  pull_request:
+    branches: [ "FRAMEWORK_6_0" ]
+  schedule:
+    - cron: "0 0 */2 * *"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Upgrade to PHP 8.3 from PPA and print PHP version
+      run: |
+        sudo add-apt-repository ppa:ondrej/php
+        sudo apt update
+        sudo apt install php8.3 php8.3-dom php8.3-pdo php8.3-sqlite3 php8.3-mysql php8.3-curl php8.3-intl php8.3-mbstring php8.3-cli php8.3-fpm
+        sudo update-alternatives --set php /usr/bin/php8.3
+        which php
+        php --version
+
+    - name: Validate composer.json and composer.lock
+      run: composer validate --strict
+
+    - name: Cache Composer packages
+      id: composer-cache
+      uses: actions/cache@v3
+      with:
+        path: vendor
+        key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-php-
+
+    - name: Install dependencies for composer.json as-is
+      run: composer install --prefer-dist --no-progress
+    - name: Install passwd app
+      run: composer require horde/passwd --prefer-dist --no-progress
+    - name: Install content tagger app
+      run: composer require horde/content --prefer-dist --no-progress
+    - name: Install timeobjects app
+      run: composer require horde/timeobjects --prefer-dist --no-progress
+    - name: Install mnemo notes app
+      run: composer require horde/mnemo --prefer-dist --no-progress
+    - name: Install ingo mail filter app
+      run: composer require horde/ingo --prefer-dist --no-progress
+    - name: Install turba addressbook app
+      run: composer require horde/turba --prefer-dist --no-progress
+    - name: Install kronolith calendar app
+      run: composer require horde/kronolith --prefer-dist --no-progress
+    - name: Install whups ticketing app
+      run: composer require horde/kronolith --prefer-dist --no-progress
+
+    # Add a test script to composer.json, for instance: "test": "vendor/bin/phpunit"
+    # Docs: https://getcomposer.org/doc/articles/scripts.md
+
+    # - name: Run test suite
+    #   run: composer run-script test