Development: Update Theia portal URL to staging for test environments (#56)

All test environments (TS1, TS2, TS3, TS9) now point to the stable
theia-staging.artemis.cit.tum.de instead of individual test cluster URLs.
This ensures developers test against the most stable Theia environment.

Co-authored-by: Matthias Linhuber <matthias.linhuber@tum.de>

Author: CodeByNikolas

group_vars/artemistest1.yml

@@ -25,7 +25,7 @@ athena:
   restricted_modules: "module_text_llm,module_programming_llm,module_modeling_llm"
 
 theia:
-  portal_url: https://test1.theia-test.artemis.cit.tum.de
+  portal_url: https://theia-staging.artemis.cit.tum.de
   images:
     java:
       Java-17: "java-17-latest"

group_vars/artemistest2.yml

@@ -13,7 +13,7 @@ athena:
   restricted_modules: "module_text_llm,module_programming_llm,module_modeling_llm"
 
 theia:
-  portal_url: https://test2.theia-test.artemis.cit.tum.de
+  portal_url: https://theia-staging.artemis.cit.tum.de
   images:
     java:
       Java-17: "java-17-latest"

group_vars/artemistest3.yml

@@ -25,7 +25,7 @@ athena:
   restricted_modules: "module_text_llm,module_programming_llm,module_modeling_llm"
 
 theia:
-  portal_url: https://test3.theia-test.artemis.cit.tum.de
+  portal_url: https://theia-staging.artemis.cit.tum.de
   images:
     java:
       Java-17: "java-17-latest"

group_vars/artemistests_theia.yml

@@ -1,6 +1,6 @@
 ---
 theia:
-  portal_url: https://test1.theia-test.artemis.cit.tum.de
+  portal_url: https://theia-staging.artemis.cit.tum.de
 
   images:
     java: