ci: bump up fetch-depth to 10 for the bootstrapping CI jobs

.github/workflows/ci_bootstrapping_works.yml

@@ -19,7 +19,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
         with:
-          fetch-depth: 5
+          fetch-depth: 10
       - name: Build v
         run: make
 
@@ -57,7 +57,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
         with:
-          fetch-depth: 5
+          fetch-depth: 10
       - name: Build V
         run: make && ./v -cg -cstrict -o v cmd/v