Temporarily disable most Ruby versions in CI

Keep only Ruby 4.0 active to speed up CI iteration. Other versions
(3.2-3.4, ruby-head, ruby-debug, truffleruby) are commented out and
can be re-enabled once CI is stable.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yahonda

.github/workflows/test.yml

@@ -13,13 +13,13 @@ jobs:
       matrix:
         ruby: [
           '4.0',
-          '3.4',
-          '3.3',
-          '3.2',
-          ruby-head,
-          ruby-debug,
-          truffleruby,
-          truffleruby-head
+          # '3.4',
+          # '3.3',
+          # '3.2',
+          # ruby-head,
+          # ruby-debug,
+          # truffleruby,
+          # truffleruby-head
         ]
     env:
       ORACLE_HOME: /usr/lib/oracle/23/client64

.github/workflows/test_11g.yml

@@ -13,13 +13,13 @@ jobs:
       matrix:
         ruby: [
           '4.0',
-          '3.4',
-          '3.3',
-          '3.2',
-          ruby-head,
-          ruby-debug,
-          truffleruby,
-          truffleruby-head
+          # '3.4',
+          # '3.3',
+          # '3.2',
+          # ruby-head,
+          # ruby-debug,
+          # truffleruby,
+          # truffleruby-head
         ]
     env:
       ORACLE_HOME: /opt/oracle/instantclient_21_15