chore(CI): Adjust testing matrix for Nextcloud 29 on stable29

Signed-off-by: Joas Schilling <[email protected]>

Author: nickvergessen

composer.json

@@ -11,7 +11,7 @@
 		"phpunit/phpunit": "^9.6",
 		"nextcloud/coding-standard": "^1.1",
 		"vimeo/psalm": "^5.16",
-		"nextcloud/ocp": "dev-master"
+		"nextcloud/ocp": "dev-stable29"
 	},
 	"config": {
 		"optimize-autoloader": true,