fix(github-cli): fix ensure_gh_extension_list_wrapper always creating gh wrapper

The check stripped GH_TOKEN along with the other auth env vars before
running `gh extension list`, but gh CLI requires some token to be
present just to run the extension subcommands, regardless of whether
listing local extensions actually needs auth. With no token and a
fresh empty GH_CONFIG_DIR, the check could never succeed, so the
/usr/local/bin/gh wrapper was installed unconditionally instead of
only when real gh actually fails to see the extensions.

Author: rhiroe

src/github-cli/scripts/install-extensions.sh

@@ -44,11 +44,11 @@ ensure_gh_extension_list_wrapper() {
 
     gh_config_dir="$(mktemp -d)"
     if env \
-        -u GH_TOKEN \
         -u GITHUB_TOKEN \
         -u GH_ENTERPRISE_TOKEN \
         -u GITHUB_ENTERPRISE_TOKEN \
         GH_CONFIG_DIR="${gh_config_dir}" \
+        GH_TOKEN="gh-extension-list-check" \
         gh extension list >/dev/null 2>&1; then
         rm -rf "${gh_config_dir}"
         return