Update test runner to stop excluding 22.x from gh actions tests

Author: zhangskz

.github/workflows/test_runner.yml

@@ -20,8 +20,8 @@ on:
     branches:
       - main
       - '[0-9]+.x'
-      # The 21.x and 22.x branches still use Kokoro
-      - '!2[12].x'
+      # The 21.x branch still uses Kokoro
+      - '!21.x'
       # For testing purposes so we can stage this on the `gha` branch.
       - gha
 
@@ -30,8 +30,8 @@ on:
     branches:
       - main
       - '[0-9]+.x'
-      # The 21.x and 22.x branches still use Kokoro
-      - '!2[12].x'
+      # The 21.x branch still uses Kokoro
+      - '!21.x'
       # For testing purposes so we can stage this on the `gha` branch.
       - gha
 
@@ -40,8 +40,8 @@ on:
     branches:
       - main
       - '[0-9]+.x'
-      # The 21.x and 22.x branches still use Kokoro
-      - '!2[12].x'
+      # The 21.x branch still uses Kokoro
+      - '!21.x'
       # For testing purposes so we can stage this on the `gha` branch.
       - gha
     types: [labeled, opened, reopened, synchronize]