Replace TemplateContextType.isInContext deprecated method

[juan-mora-google]

Description

Replaced deprecated method isInContext from TemplateContextType class in DartTemplateContextType.java file

Testing steps:

1. Run the IDE in Sandbox mode with the plugin
2. Prepare a Live Template for testing
Inside the Sandbox IDE window:

• Go to the IDE settings (Settings / Preferences).
• Navigate to Editor > Live Templates.
• Click the + (Add) button and select Live Template.
• Give it an abbreviation (e.g., dtest) and some template code (e.g., print('hello');).
• At the bottom, you will see a red warning saying "No applicable contexts". Click Define.
• Find Dart option (which matches the contextId registered in the plugin.xml) and check it.
• Apply.

3. Test the "Happy Path" (It should work)

• Create a .dart file inside the Sandbox IDE
• Start typing the abbreviation previously defined (dtest).
• The IDE should suggest the template. If you press Tab, the code will expand. This confirms that file.getLanguage() instanceof DartLanguage evaluated to true.

4. Test the "Negative Path" (It should not work)

• Create a file with a different extension in the same project, for example test.java or test.txt.
• Attempt to type the abbreviation (dtest).
• The IDE should not suggest or expand the template, since the condition requiring it to be a DartLanguage file is not met.

---

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[gemini-code-assist]

Code Review

This pull request updates the isInContext method in DartTemplateContextType to accept a TemplateActionContext parameter instead of PsiFile and offset, aligning with modern IntelliJ Platform APIs. The review feedback correctly points out that the @Override annotation was omitted during this refactoring and should be restored to maintain compile-time safety.

[helin24]

Looks reasonable to me and I see tests are passing!

Can you add to the description how we can manually test that this is working? e.g. what user activity would trigger this code path, what should happen, and what could we expect if this change has broken it? (I'm going to add to our PR template to note that this is relevant for most PRs)

[juan-mora-google]

Looks reasonable to me and I see tests are passing!

Can you add to the description how we can manually test that this is working? e.g. what user activity would trigger this code path, what should happen, and what could we expect if this change has broken it? (I'm going to add to our PR template to note that this is relevant for most PRs)

These are the steps to repro:
1. Run the IDE in Sandbox mode with the plugin
2. Prepare a Live Template for testing
Inside the Sandbox IDE window:

• Go to the IDE settings (Settings / Preferences).
• Navigate to Editor > Live Templates.
• Click the + (Add) button and select Live Template.
• Give it an abbreviation (e.g., dtest) and some template code (e.g., print('hello');).
• At the bottom, you will see a red warning saying "No applicable contexts". Click Define.
• Find Dart option (which matches the contextId registered in the plugin.xml) and check it.
• Apply.

3. Test the "Happy Path" (It should work)

• Create a .dart file inside the Sandbox IDE
• Start typing the abbreviation previously defined (dtest).
• The IDE should suggest the template. If you press Tab, the code will expand. This confirms that file.getLanguage() instanceof DartLanguage evaluated to true.

4. Test the "Negative Path" (It should not work)

• Create a file with a different extension in the same project, for example test.java or test.txt.
• Attempt to type the abbreviation (dtest).
• The IDE should not suggest or expand the template, since the condition requiring it to be a DartLanguage file is not met.

[juan-mora-google]

Closing this PR due to CLA problems