Revert "fix: add fail-fast: false to prevent cascade cancellations in matrix build"

This reverts commit da0682f.

Author: claude

.github/workflows/build-protoc.yml

@@ -15,7 +15,6 @@ jobs:
     strategy:
       # ensure protoc is built first
       max-parallel: 1
-      fail-fast: false
       matrix:
         image:
           - protoc