Fix VSIX verification to use unzip instead of vsce ls

vsce ls does not support --packagePath. Use unzip -l to check
whether bin/git-crypt is present in platform-specific packages
and absent from the universal package.

Author: j-256

.github/workflows/ci.yml

@@ -152,11 +152,15 @@ jobs:
         run: |
           for f in git-crypt-vscode-*-*.vsix; do
             echo "=== $f ==="
-            npx vsce ls --packagePath "$f" | grep -c 'bin/git-crypt' | xargs -I{} test {} -eq 1
+            unzip -l "$f" | grep -q 'bin/git-crypt' || { echo "FAIL: bin/git-crypt missing from $f"; exit 1; }
           done
           echo "=== universal ==="
           UNIVERSAL=$(ls git-crypt-vscode-*.vsix | grep -v -- '-darwin\|-linux')
-          npx vsce ls --packagePath "$UNIVERSAL" | grep -c 'bin/git-crypt' | xargs -I{} test {} -eq 0
+          if unzip -l "$UNIVERSAL" | grep -q 'bin/git-crypt'; then
+            echo "FAIL: bin/git-crypt should not be in universal $UNIVERSAL"
+            exit 1
+          fi
+          echo "All VSIX contents verified"
 
       - name: Create or update GitHub release
         if: startsWith(github.ref, 'refs/tags/v')