Upgrade version of Android Studio

[helin24]

The motivations for this change:

• The latest Dart plugin (v505) has been released, so we should start depending on it.
• Android Studio Panda (2025.3) is now the stable release, so we should build against it.

Some other changes followed from those updates:

• I had to add lsp4ij as a dependency since Dart depends on it now. bytebuddy was also added as a new dependency (for mockito, I think?)
• intellij.platform.langInjection" is now a module replacing org.intellij.intelliLang (old plugin). See notes on 253: org.intellij.intelliLang is reported as bundled module, but it's unavailable JetBrains/intellij-platform-gradle-plugin#2026
• Verification ran into an issue that I couldn't fix by running update_baselines.sh - more info below.

More on the verification issue:

• When I generate baselines for 2025.3, it produces a line that keeps parameter names, e.g. * Deprecated constructor com.jetbrains.lang.dart.ide.template.DartTemplateContextType.<init>(java.lang.String id, java.lang.String presentableName, java.lang.Class baseContextType) is invoked in io.flutter.template.DartToplevelTemplateContextType.<init>()
• On CI, verify does not preserve parameter names, so it finds * Deprecated constructor com.jetbrains.lang.dart.ide.template.DartTemplateContextType.<init>(java.lang.String arg0, java.lang.String arg1, java.lang.Class arg2) is invoked in io.flutter.template.DartToplevelTemplateContextType.<init>()
• I could potentially ask CI to always generate verification reports with parameters, but this actually requires a change to Dart plugin, not Flutter plugin. So while I could do that, it would require releasing Dart again and updating the version dependency here again, which seems like a lot...
• Instead I'm asking github.sh to instead match the class name and ignore the params. Hopefully that works.

[gemini-code-assist]

Code Review

This pull request updates the IntelliJ platform version to 2025.3.4.6, the Dart plugin to 505.0.0, and the IntelliJ platform plugin to 2.16.0. It also transitions from the intelliLang plugin dependency to the intellij.platform.langInjection bundled module. A logical issue was identified where the CI verification script (tool/github.sh) needs to be updated to include the new build version (253) introduced by the version bump to ensure the plugin is correctly verified in CI.

[pq]

Ok. I'll stop resisting 🙃

Thanks for all the follow-up!

[helin24]

Haha we can also discuss later, along with why our build takes an hour 😢

It's not a very pleasant set of changes.

[pq]

Oof. An hour? Let's talk.