consistent cache path to ensure hit

Change-Id: Ic57ecc47db239f0340e225f464a1809e02bee712
Signed-off-by: Tom Proctor <tomhjp@users.noreply.github.com>

.github/workflows/test.yml

@@ -240,15 +240,13 @@ jobs:
     - name: Restore Go module cache
       uses: actions/cache/restore@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
       with:
-        path: ${{ github.workspace }}/gomodcache
+        path: gomodcache
         key: ${{ needs.gomod-cache.outputs.cache-key }}
         enableCrossOsArchive: true
 
     - name: Setup cigocacher
       id: cigocacher-setup
       uses: ./src/.github/actions/go-cache
-      env:
-        GOMODCACHE: ${{ github.workspace }}/gomodcache
       with:
         checkout-path: ${{ github.workspace }}/src
         cache-dir: ${{ github.workspace }}/cigocacher
@@ -257,15 +255,11 @@ jobs:
     - name: test
       if: matrix.key != 'win-bench' # skip on bench builder
       working-directory: src
-      env:
-        GOMODCACHE: ${{ github.workspace }}/gomodcache
       run: go run ./cmd/testwrapper sharded:${{ matrix.shard }}
 
     - name: bench all
       if: matrix.key == 'win-bench'
       working-directory: src
-      env:
-        GOMODCACHE: ${{ github.workspace }}/gomodcache
       # Don't use -bench=. -benchtime=1x.
       # Somewhere in the layers (powershell?)
       # the equals signs cause great confusion.