Build MacOS on macos-26

macos-latest is still 15. We should be building on 26 to ensure compatibility.

Signed-off-by: nmburgan <13688219+nmburgan@users.noreply.github.com>

Author: nmburgan

.github/workflows/build_vanagon.yml

@@ -94,11 +94,11 @@ jobs:
           for platform in "${platforms[@]}"; do
             case "$platform" in
               macos-*-x86_64)
-                runner="macos-latest"
+                runner="macos-26"
                 shell="arch -x86_64 /bin/bash -e {0}"
                 ;;
               macos-*-arm64)
-                runner="macos-latest"
+                runner="macos-26"
                 shell="bash"
                 ;;
               windows-*)