tests: tweak parallelism

Author: ctrombley

.github/actions/test-go-tfe/action.yml

@@ -122,7 +122,7 @@ runs:
         GO111MODULE: "on"
         ENABLE_TFE: ${{ inputs.enterprise }}
       run: |
-        gotestsum --junitfile summary.xml --format short-verbose --rerun-fails=3 --packages=./ -- -parallel=4 -timeout=59m -coverprofile cover.out -run "${{ steps.test_split.outputs.run }}" ${{ inputs.skip-statement }}
+        gotestsum --junitfile summary.xml --format short-verbose --rerun-fails=3 --packages=./ -- -parallel=2 -timeout=59m -coverprofile cover.out -run "${{ steps.test_split.outputs.run }}" ${{ inputs.skip-statement }}
 
     - name: Upload test artifacts
       uses: actions/upload-artifact@65c4c4a1ddee5b72f698fdd19549f0f0fb45cf08 # v4.6.0