fix: update cache key format in build workflow

Author: vkhinvasara

.github/workflows/build.yaml

@@ -41,7 +41,7 @@ jobs:
             ~/.cargo/registry
             ~/.cargo/git
             target
-          key: ${{ runner.os }}-cargo-${{ matrix.target }}-default-v2-${{ hashFiles('**/Cargo.lock') }}
+          key: ${{ runner.os }}-cargo-${{ matrix.target }}-default-${{ hashFiles('**/Cargo.lock') }}
       - name: Build
         uses: actions-rs/cargo@v1
         with: