minor: Re-enable GCS-backed sccache in Windows CI Pipeline (#1542)

* chore: enabling sccache for windows release

---------

Co-authored-by: Sachin Purohit <sachinpurohit@google.com>

Author: Anshu6250

.github/workflows/windows-cmake.yml

@@ -115,7 +115,6 @@ jobs:
 
         # TODO(b/513099808): Re-enable after fixing intermittent GCS I/O errors causing flaky builds.
         export SCCACHE_IGNORE_SERVER_IO_ERROR=1
-        unset SCCACHE_GCS_BUCKET SCCACHE_GCS_KEY_PREFIX SCCACHE_GCS_RW_MODE
 
         export MSVC_VERSION="${{ matrix.msvc }}"
         export BRANCH_IDENTIFIER=$(echo "${{ github.ref_name }}" | tr '[:punct:]' '_')

.github/workflows/windows-release.yml

@@ -115,7 +115,6 @@ jobs:
         export CLOUDSDK_PYTHON="${{ steps.py311.outputs.python-path }}"
         export CMAKE_OUT="c:/b"
         export SCCACHE_IGNORE_SERVER_IO_ERROR=1
-        unset SCCACHE_GCS_BUCKET SCCACHE_GCS_KEY_PREFIX SCCACHE_GCS_RW_MODE
 
         export MSVC_VERSION="${{ matrix.msvc }}"
         export BRANCH_IDENTIFIER=$(echo "${{ github.ref_name }}" | tr '[:punct:]' '_')