Revert CI workflow changes as requested

Co-authored-by: AtsushiSakai <[email protected]>

Author: Copilot

.github/workflows/Linux_CI.yml

@@ -19,7 +19,6 @@ jobs:
     steps:
     - uses: actions/checkout@v5
     - run: git fetch --prune --unshallow
-    - run: git fetch origin master:master
 
     - name: Setup python
       uses: actions/setup-python@v6

.github/workflows/MacOS_CI.yml

@@ -21,7 +21,6 @@ jobs:
     steps:
       - uses: actions/checkout@v5
       - run: git fetch --prune --unshallow
-      - run: git fetch origin master:master
 
       - name: Update bash
         run: brew install bash

.github/workflows/Windows_CI.yml

@@ -21,7 +21,6 @@ jobs:
     steps:
       - uses: actions/checkout@v5
       - run: git fetch --prune --unshallow
-      - run: git fetch origin master:master
 
       - name: Setup python
         uses: actions/setup-python@v6