Remove kotlin cross tests (#3236)

- They have been failing for months now without any actions
- The red builds have already desensitized the project to checking for failures

Author: CJCombrink

.github/workflows/build.yml

@@ -629,9 +629,10 @@ jobs:
     strategy:
       matrix:
         # swift is currently broken and no maintainers around -> see THRIFT-5864
-        server_lang: ['java', 'kotlin', 'go', 'rs', 'cpp']   # ['java', 'kotlin', 'go', 'rs', 'swift']
+        # kotlin cross test are failing -> see THRIFT-5879
+        server_lang: ['java', 'go', 'rs', 'cpp']
         # we always use comma join as many client langs as possible, to reduce the number of jobs
-        client_lang: ['java,kotlin', 'go,rs,cpp']    # ['java,kotlin', 'go,rs', 'swift']
+        client_lang: ['java', 'go,rs,cpp']
       fail-fast: false
     steps:
       - uses: actions/checkout@v5