bug: matplotlib update to remove deprecation warnings (FXC-4658)

[daquinteroflex]

Greptile Summary

This PR updates the matplotlib dependency constraint from * (any version) to >=3.10.0 to eliminate deprecation warnings when using newer matplotlib versions. The change only affects the dependency specification in pyproject.toml and the corresponding lock file - no code changes are required.

Key changes:

• Updated matplotlib version constraint to >=3.10.0 in pyproject.toml:33
• Updated poetry.lock with new dependency resolutions (also includes updates to boto3, botocore, mistune, nbclient, and pyparsing)

Issues identified:

• Check that a changelog entry is added for this bug fix, as per the repository's custom instructions (rule b72c7231-b258-4d03-aed2-51a50a9fe757)

Confidence Score: 5/5

• This PR is safe to merge with minimal risk - it's a straightforward dependency version constraint update
• Score of 5 reflects that this is a low-risk dependency update that only adds a minimum version constraint (not breaking changes), follows semantic versioning best practices, and requires no code modifications. The only concern is a missing changelog entry per repository guidelines.
• No files require special attention - the changes are standard dependency updates

Important Files Changed

Filename	Overview
pyproject.toml	Updated matplotlib version constraint from * to >=3.10.0 to address deprecation warnings
poetry.lock	Updated lock file with new dependency versions including boto3, botocore, mistune, nbclient, and pyparsing

Sequence Diagram

sequenceDiagram
    participant Dev as Developer
    participant PyPrj as pyproject.toml
    participant Poetry as Poetry Lock
    participant MatPlot as Matplotlib (>=3.10.0)
    
    Dev->>PyPrj: Update matplotlib constraint<br/>from "*" to ">=3.10.0"
    Dev->>Poetry: Run poetry lock
    Poetry->>MatPlot: Resolve matplotlib >=3.10.0
    Poetry->>Poetry: Update dependency hashes
    Note over Poetry: Also updates:<br/>boto3, botocore, mistune,<br/>nbclient, pyparsing
    Poetry-->>Dev: Lock file updated
    Note over Dev,MatPlot: Matplotlib 3.10.0+ deprecation<br/>warnings resolved

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Context used:

• Rule from dashboard - Require a changelog entry for any PR that is not purely an internal refactor. (source)

---

Note

Low Risk
Small, localized visualization change plus dependency constraint/lockfile updates; minimal behavioral impact outside plotting and packaging.

Overview
Fixes a matplotlib deprecation warning in scene permittivity plotting by switching Scene._get_structure_eps_plot_params to use mpl.colormaps.get_cmap() instead of indexing mpl.colormaps[...].

Relaxes the matplotlib dependency constraint in pyproject.toml to >=3.7.0,<4.0.0 and updates poetry.lock accordingly (including a few minor transitive version/marker adjustments). Adds a towncrier entry in changelog.d/3121.fixed.md.

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Diff Coverage

Diff: origin/develop...HEAD, staged and unstaged changes

• tidy3d/components/scene.py (100%)

Summary

• Total: 1 line
• Missing: 0 lines
• Coverage: 100%

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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Incompatible API used with relaxed minimum version constraint

Medium Severity

The minimum matplotlib version was lowered from 3.10.0 to 3.7.0, but the code was simultaneously changed from mpl.colormaps[cmap_name] (bracket access, available since 3.5) to mpl.colormaps.get_cmap(cmap_name). The ColormapRegistry.get_cmap() method was not part of the original ColormapRegistry API introduced in 3.5 (which only had __getitem__ and register). Users with matplotlib versions between 3.7.0 and wherever get_cmap() was added would get an AttributeError. The bracket notation mpl.colormaps[cmap_name] is equally non-deprecated and compatible with all versions since 3.5.

Additional Locations (1)

• pyproject.toml#L32-L33