Use Xcode 26.6 and Ruby 3.4.9 (#25748)

* Require Xcode 26.6 in CI

* Use Ruby 3.4.9 and re-bundle with latest Bundler, 4.0.15

Also notice that config has been update to enforce building with native
extensions, so that the lockfile stays tidy and doesn't produce noise.

This behavior had been flaky in previous Xcode toolchain and because we
didn't have newer Ruby versions available.

* Trust FelixHerrmann tap for newer Homebrew

The Xcode 26.6 image ships a Homebrew that enforces tap trust and refuses
to load `swift-package-list` from the untrusted `FelixHerrmann/tap`, failing
the Homebrew dependency install step.

---

Generated with the help of Claude Code, https://claude.ai/code

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Drop dead BUNDLE_SPECIFIC_PLATFORM bundler setting

Bundler stopped reading `specific_platform` in 2.2.0 (2020-12-10): commit
`0bcf7492d` deleted its `settings_flag`, making platform-specific gem
resolution unconditional. The `"false"` value has been a no-op since.

---

Generated with the help of Claude Code, https://claude.ai/code

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Remove verbose AI comment

Co-authored-by: Gio Lodi <giovanni.lodi42@gmail.com>

* Extract swift-package-list install to shared script

The `FelixHerrmann/tap` tap/trust/install block was duplicated in
`build-for-testing.sh` and `shared-set-up-distribution.sh` — the two CI
paths that build a shippable app and thus need the acknowledgements build
phase's `swift-package-list`. Centralize it so the tap-trust incantation
has one home.

---

Generated with the help of Claude Code, https://claude.ai/code

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Disable Homebrew ask-mode to unblock CI installs

Homebrew 6 enables ask-mode by default: `brew install` prints its plan and
prompts for confirmation when it pulls in dependencies. The prompt is meant
to be skipped without a TTY, but Buildkite allocates a PTY, so `brew install
imagemagick` hung waiting for input that never came.

---

Generated with the help of Claude Code, https://claude.ai/code

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Move one CI log header print to the script the log is about

* Double quote to avoid word splitting in `build-for-testing.sh`

* Only run `brew trust` where available

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: 3 people

.buildkite/commands/build-for-testing.sh

@@ -12,9 +12,7 @@ if [[ "$APP" != "wordpress" && "$APP" != "jetpack" ]]; then
   exit 1
 fi
 
-echo "--- :beer: Installing Homebrew Dependencies"
-brew tap FelixHerrmann/tap
-brew install swift-package-list
+"$(dirname "${BASH_SOURCE[0]}")/install-swift-package-list.sh"
 
 "$(dirname "${BASH_SOURCE[0]}")/shared-set-up.sh"
 
@@ -26,8 +24,8 @@ echo "--- :closed_lock_with_key: Installing Secrets"
 bundle exec fastlane run configure_apply
 
 echo "--- :hammer_and_wrench: Building"
-bundle exec fastlane build_${APP}_for_testing
+bundle exec fastlane "build_${APP}_for_testing"
 
 echo "--- :arrow_up: Upload Build Products"
-tar -cf build-products-${APP}.tar DerivedData/Build/Products/
-upload_artifact build-products-${APP}.tar
+tar -cf "build-products-${APP}.tar" DerivedData/Build/Products/
+upload_artifact "build-products-${APP}.tar"

.buildkite/commands/install-swift-package-list.sh

@@ -0,0 +1,8 @@
+#!/bin/bash -eu
+
+echo "--- :beer::swift: Installing swift-package-list via Homebrew"
+brew tap FelixHerrmann/tap
+if brew help trust >/dev/null 2>&1; then
+  brew trust FelixHerrmann/tap
+fi
+brew install swift-package-list

.buildkite/commands/shared-set-up-distribution.sh

@@ -1,11 +1,13 @@
 #!/bin/bash -eu
 
+# Homebrew 6 ask-mode prompts before installing dependencies and hangs on the CI PTY.
+export HOMEBREW_NO_ASK=1
+
 echo "--- :beer: Installing Homebrew Dependencies"
 # Sentry CLI needs to be up-to-date
 brew upgrade sentry-cli
 
-brew tap FelixHerrmann/tap
-brew install swift-package-list
+"$(dirname "${BASH_SOURCE[0]}")/install-swift-package-list.sh"
 
 brew install imagemagick
 brew install ghostscript

.bundle/config

@@ -3,4 +3,4 @@ BUNDLE_PATH: "vendor/bundle"
 BUNDLE_JOBS: "3"
 BUNDLE_WITHOUT: "screenshots"
 BUNDLE_RETRY: "3"
-BUNDLE_SPECIFIC_PLATFORM: "false"
+BUNDLE_FORCE_RUBY_PLATFORM: "true"

.ruby-version

@@ -1 +1 @@
-3.2.2
+3.4.9

.xcode-version

@@ -1 +1 @@
-26.4.1
+26.6

Gemfile.lock

@@ -399,4 +399,4 @@ DEPENDENCIES
   rubocop-rake (~> 0.7)
 
 BUNDLED WITH
-   2.4.22
+   4.0.15