ci: restore Ruby PATH export for fastlane step

act_runner does not carry setup-ruby's PATH changes into later steps,
so without this the step runs the toolcache default Ruby (3.3.11) and
bundler cannot find the gems installed for 3.1.7.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.gitea/workflows/testflight.yml

@@ -36,4 +36,9 @@ jobs:
           SYBIL_BUILD_NUMBER: ${{ github.run_number }}
           FASTLANE_SKIP_UPDATE_CHECK: "1"
           FASTLANE_XCODEBUILD_SETTINGS_TIMEOUT: "120"
-        run: bundle exec fastlane ios beta
+        # act_runner does not propagate setup-ruby's PATH changes into later
+        # steps, so put the selected Ruby back on PATH or `bundle` resolves to
+        # the toolcache default and misses the gems installed above.
+        run: |
+          export PATH="/Users/runner/hostedtoolcache/Ruby/3.1.7/arm64/bin:${PATH}"
+          bundle exec fastlane ios beta