Set continue-on-error: false for CI workflows in this PR

Flip continue-on-error from true to false on the test, test_11g,
test_11g_ojdbc11, and jruby_head workflows so that a failed CI job
actually fails the suite. continue-on-error: true makes job results
"green even when red", and in practice failures under that mode tend
to be ignored — defeating the purpose of running the job at all.

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

Author: yahonda

.github/workflows/jruby_head.yml

@@ -8,7 +8,7 @@ jobs:
   build:
 
     runs-on: ubuntu-latest
-    continue-on-error: true
+    continue-on-error: false
     strategy:
       matrix:
         ruby: [

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
   build:
 
     runs-on: ubuntu-latest
-    continue-on-error: true
+    continue-on-error: false
     strategy:
       matrix:
         ruby: [

.github/workflows/test_11g.yml

@@ -12,7 +12,7 @@ jobs:
     if: github.event_name != 'pull_request' || !github.event.pull_request.draft
 
     runs-on: ubuntu-latest
-    continue-on-error: true
+    continue-on-error: false
     strategy:
       matrix:
         ruby: [

.github/workflows/test_11g_ojdbc11.yml

@@ -12,7 +12,7 @@ jobs:
     if: github.event_name != 'pull_request' || !github.event.pull_request.draft
 
     runs-on: ubuntu-latest
-    continue-on-error: true
+    continue-on-error: false
     strategy:
       matrix:
         ruby: [