iOS/macOS: build with XCode 26.0

It seems to be a new requirement for Chromium:
https://chromium.googlesource.com/chromium/src/build/+/0a45979d9ff0f959bed73f641668feec5eac7ad5

Before this change, the iOS builds failed with the following error:

ninja: error: '/Applications/Xcode_15.0.1.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.0.sdk/usr/include/DarwinBasic.modulemap', needed by 'obj/buildtools/third_party/libc++/MachO/DarwinBasic.pcm', missing and no known rule to make it

And the macOS builds failed with this one:

ninja: error: '/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/DarwinBasic.modulemap', needed by 'obj/buildtools/third_party/libc++/MachO/DarwinBasic.pcm', missing and no known rule to make it

Author: bblanchon

.github/workflows/build.yml

@@ -54,7 +54,7 @@ jobs:
   build:
     outputs:
       artifact: ${{ steps.init.outputs.artifact }}
-    runs-on: ${{ (inputs.target_os == 'ios' || inputs.target_os == 'mac') && 'macos-14' || inputs.target_os == 'win' && 'windows-2022' || 'ubuntu-24.04' }}
+    runs-on: ${{ (inputs.target_os == 'ios' || inputs.target_os == 'mac') && 'macos-15' || inputs.target_os == 'win' && 'windows-2022' || 'ubuntu-24.04' }}
     env:
       PDFium_BRANCH: ${{ inputs.branch }}
       PDFium_IS_DEBUG: ${{ inputs.is_debug }}

steps/01-install.sh

@@ -97,10 +97,8 @@ case "$TARGET_OS" in
     echo "$WindowsSDK_DIR/$CURRENT_CPU" >> "$PATH_FILE"
     ;;
 
-  ios)
-    # Xcode 15.4 produces the following error when targeting ARM64 with V8:
-    # undefined symbol: be_memory_inline_jit_restrict_rwx_to_rx_with_witness_impl
-    sudo xcode-select -s "/Applications/Xcode_15.0.1.app"
+  mac|ios)
+    sudo xcode-select -s "/Applications/Xcode_26.0.app"
     ;;
 
   emscripten)

steps/05-configure.sh

@@ -42,7 +42,6 @@ mkdir -p "$BUILD"
       echo "clang_use_chrome_plugins = false"
       ;;
     mac)
-      echo 'mac_deployment_target = "11.0.0"'
       echo "clang_use_chrome_plugins = false"
       ;;
     emscripten)