[ci] Check macOS 15 for Xcode analyzer warnings (flutter#9427)

Xcode 16 is available in CI as of flutter/packages#8968. Check all packages for macOS 15 deprecations.

The last bump flutter/packages#7544

Related flutter/plugins#5778 and flutter#102835

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Author: jmagman

.ci/targets/macos_platform_tests.yaml

@@ -15,7 +15,7 @@ tasks:
   - name: xcode analyze deprecation
     # Ensure we don't accidentally introduce deprecated code.
     script: .ci/scripts/tool_runner.sh
-    args: ["xcode-analyze", "--macos", "--macos-min-version=14.0", "--exclude=script/configs/exclude_xcode_deprecation.yaml,script/configs/xcode_warnings_exceptions.yaml"]
+    args: ["xcode-analyze", "--macos", "--macos-min-version=15.0", "--exclude=script/configs/exclude_xcode_deprecation.yaml,script/configs/xcode_warnings_exceptions.yaml"]
   - name: native test
     script: .ci/scripts/tool_runner.sh
     args: ["native-test", "--macos", "--xcode-warnings-exceptions=script/configs/xcode_warnings_exceptions.yaml"]