Bugfix/regex arithmetic

[Dooruk]

The regex change abs was replacing absoluteDynamicTopography from the ocean obs. It took me a bit to identify this bug..

[Copilot]

Pull Request Overview

This PR fixes a regex bug where function names were being incorrectly matched as substrings, causing unintended replacements. The fix adds word boundaries to ensure exact function name matching in arithmetic expressions.

• Adds word boundary anchors (\b) to regex pattern for function names in arithmetic expressions
• Updates package version constraints in requirements file to use more flexible versioning

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/eva/transforms/arithmetic.py	Fixes regex pattern to prevent partial function name matches
requirements_sles15.txt	Updates package version constraints for better compatibility

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[Dooruk]

Sorry to bug you for this bug @CoryMartin-NOAA but I need write approval.

[Dooruk]

Also @mranst apparently this was my problem with EVA, not the package versions.

GEOS-ESM/swell#549

[karpob]

This looks reasonable to me, I feel like there must be a better way to do what arithmetic does in general. Using regex for this seems like there may be unintended consequences based on what the user may input.