chore(CI) : adjust testing matrix for Nextcloud stable29

Signed-off-by: Hamza Mahjoubi <hamzamahjoubi221@gmail.com>

[skip ci]

.github/workflows/phpunit.yml

@@ -20,7 +20,7 @@ jobs:
       matrix:
         php-versions: ['8.0']
         databases: ['sqlite']
-        server-versions: ['master', 'stable28', 'stable27', 'stable26', 'stable25']
+        server-versions: ['stable29', 'stable28', 'stable27', 'stable26', 'stable25']
         include:
           - php-versions: '7.4'
             server-versions: stable25
@@ -90,10 +90,10 @@ jobs:
       matrix:
         php-versions: ['8.1', '8.2', '8.3']
         databases: ['mysql']
-        server-versions: ['master']
+        server-versions: ['stable29']
         include:
           - php-versions: '8.0'
-            server-versions: 'master'
+            server-versions: 'stable29'
             databases: 'mysql'
           - php-versions: '7.4'
             server-versions: stable25
@@ -167,7 +167,7 @@ jobs:
       matrix:
         php-versions: ['8.0']
         databases: ['pgsql']
-        server-versions: ['master']
+        server-versions: ['stable29']
         include:
           - php-versions: '7.4'
             server-versions: stable25