Update workflows (#89)

* Remove unused workflows

Releases are now handled by a fork of jupyter-releaser

* Unpin jlab version in tests

* Update ui test

Author: IsabelParedes

.github/workflows/build.yml

@@ -107,7 +107,7 @@ jobs:
         init-shell: bash
         create-args: >-
           python
-          jupyterlab==4.0
+          jupyterlab>=4.0
 
     - name: Download extension package
       uses: actions/download-artifact@v4

.github/workflows/prep-release.yml

@@ -10,6 +10,6 @@
   },
   "devDependencies": {
     "@jupyterlab/galata": "^5.0.0",
-    "@playwright/test": "^1.32.0"
+    "@playwright/test": "^1.37.0"
   }
 }