CI: use explicit version tags for macos runners (#14548)

as we do on others like ubuntu

Signed-off-by: Philip H <47042125+pheiduck@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0120c8f..4f60216 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -313,7 +313,7 @@
       fail-fast: false
       matrix:
         features: [tiny, normal, huge]
-        runner: [macos-latest, macos-14]
+        runner: [macos-12, macos-14]
 
     steps:
       - name: Checkout repository from github