Update PET and Topmodel to get bug, sanitizer/valgrind, and -Werror fixes

[PhilMiller]

Changes

• Update PET, particularly to get Fix warnings to support -Werror in Github CI evapotranspiration#35
• Update Topmodel, particularly to get Fix memory error when chv and rv are used as calibration parameters. topmodel#46 and Address compiler and valgrind/sanitizer warnings topmodel#47

Fixes #776

Testing

1. Github CI

Checklist

• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows project standards (link if applicable)
• Passes all existing automated tests
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future todos are captured in comments
• Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)
• Reviewers requested with the Reviewers tool ➡️

Target Environment support

• Linux
• macOS