CompatHelper: bump compat for ModelingToolkit to 11 for package test, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the ModelingToolkit package from 10 to 10, 11 for package test.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[ChrisRackauckas-Claude]

Analysis of Dependency Update

I've analyzed this PR that attempts to add compatibility for ModelingToolkit v11 to the test dependencies.

Issue Found

The dependency update cannot proceed due to a compatibility constraint:

• MethodOfLines v0.11 (used in tests) only supports ModelingToolkit v10.1.0 - 10.x
• MethodOfLines v0.11 does NOT support ModelingToolkit v11

When attempting to install both dependencies with ModelingToolkit = "10, 11", the package resolver fails:

ERROR: Unsatisfiable requirements detected for package ModelingToolkit [961ee093]:
 └─restricted by compatibility requirements with MethodOfLines [94925ecb] to versions: [9.7.1 - 9.84.0, 10.1.0 - 10.31.2] — no versions left

Current Status

• Tests pass with ModelingToolkit v10.31.2 (current constraint)
• ModelingToolkit v11.4.0 is available in the registry
• MethodOfLines has not yet released a version compatible with ModelingToolkit v11

Recommended Action

This PR should be held until:

1. MethodOfLines releases a version compatible with ModelingToolkit v11, OR
2. The test suite is refactored to not depend on MethodOfLines

@ChrisRackauckas Should we close this PR for now and wait for MethodOfLines to support MTK v11?

🤖 Generated with Claude Code

[ChrisRackauckas]

Wait for MethodOfLines