Fix minimum version bounds for ModelingToolkitBase dependencies

[ChrisRackauckas-Claude]

Summary

This PR fixes incorrect lower bounds for several dependencies. The existing bounds were set lower than what ModelingToolkitBase 1.0.0 actually requires, which could cause resolution conflicts when users have older package versions installed.

Updated bounds:

• DiffEqBase: 6.152 → 6.189.1 (required by ModelingToolkitBase 1.x)
• PreallocationTools: 0.4.23 → 0.4.27 (required by ModelingToolkitBase 1.x)
• SciMLStructures: 1.4.2 → 1.7.0 (required by ModelingToolkitBase 1.x)
• SymbolicIndexingInterface: 0.3.28 → 0.3.39 (required by ModelingToolkitBase 1.x)

How the issue was discovered

When attempting to resolve a package environment with the minimum versions specified in the compat bounds, the Julia package resolver reported conflicts. For example:

ERROR: Unsatisfiable requirements detected for package PreallocationTools [d236fae5]:
 PreallocationTools [d236fae5] log:
 └─restricted by compatibility requirements with ModelingToolkitBase [7771a370] to versions: 0.4.27 - 0.4.34 — no versions left

This happens because ModelingToolkitBase 1.0.0's compat requirements specify minimum versions higher than what was listed in this package's compat.

Test plan

• Package loads successfully with updated bounds
• All tests pass (573 passed, with 1 fail and 1 error that are pre-existing issues not related to this change)

cc @ChrisRackauckas

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