fix CI again.

.github/workflows/CI.yml

@@ -4,7 +4,6 @@ on:
   push:
     branches:
       - main
-      - master
     tags:
       - 'v*'
   workflow_dispatch:
@@ -15,15 +14,18 @@ permissions:
 jobs:
   check-rust:
     runs-on: ubuntu-latest
+    if: startsWith(github.ref, 'refs/tags/v')
     steps:
       - name: Check Rust Compiler and Cargo
         run: |
           rustc --version
           cargo --version
 
   build-and-test:
+
     needs: check-rust
     runs-on: ${{ matrix.platform.runner }}
+    if: startsWith(github.ref, 'refs/tags/v')
     strategy:
       matrix:
         platform:
@@ -62,6 +64,7 @@ jobs:
   pypi-publish:
     name: Upload release to PyPI
     runs-on: ubuntu-latest
+    if: startsWith(github.ref, 'refs/tags/v')
     needs: [build-and-test]  # Ensure this job waits for others to finish
     environment:
       name: pypi