github/workflow: remove fetch-depth 2

Signed-off-by: Koichi Shiraishi <[email protected]>

Author: zchee

.github/workflows/test.yml

@@ -46,8 +46,6 @@ jobs:
 
     - name: Checkout code
       uses: actions/checkout@v2
-      with:
-        fetch-depth: 2
 
     - name: Cache Go module and build cache
       uses: actions/cache@v2