Resolve 7 SonarQube Reliability issues in METplotpy's develop branch

[jprestop]

Describe the Task

After ugrading to SonarQube v2025.3.1, the categories of SonarQube findings have changed slightly. Security issues (previously called Vulnerability) must be zero for each release. Reliability issues (previously Bugs) should be minimized, ideally down to zero. Maintainability issues (previously Code Smells) should be reduced where feasible.

As of Oct 8, 2025, METplotpy's develop branch contains 0 Security, 7 Reliability, and 367 Maintainability issues. This task is to address and resolve the 7 Reliability issues from METplotpy's develop branch.

Time Estimate

Estimate the amount of work required here.
Issues should represent approximately 1 to 3 days of work.

Sub-Issues

Consider breaking the task down into sub-issues.

• Add a checkbox for each sub-issue here.

Relevant Deadlines

List relevant project deadlines here or state NONE.

Funding Source

2025 USAF METplus funding

Define the Metadata

Assignee

• Select engineer(s) or no engineer required
• Select scientist(s) or no scientist required

Labels

• Review default alert labels
• Select component(s)
• Select priority
• Select requestor(s)

Milestone and Projects

• Select Milestone as a METplotpy-X.Y.Z version, Consider for Next Release, or Backlog of Development Ideas
• For a METplotpy-X.Y.Z version, select the METplotpy-X.Y.Z Development project

Define Related Issue(s)

Consider the impact to the other METplus components.

• METplus, MET, METdataio, METviewer, METexpress, METcalcpy, METplotpy

Task Checklist

See the METplus Workflow for details.

• Complete the issue definition above, including the Time Estimate and Funding Source.
• Fork this repository or create a branch of develop.
  Branch name: feature_<Issue Number>_<Description>
• Complete the development and test your changes.
• Add/update log messages for easier debugging.
• Add/update unit tests.
• Add/update documentation.
• Add any new Python packages to the METplus Components Python Requirements table.
• Push local changes to GitHub.
• Submit a pull request to merge into develop.
  Pull request: feature <Issue Number> <Description>
• Define the pull request metadata, as permissions allow.
  Select: Reviewer(s) and Development issue
  Select: Milestone as the next official version
  Select: METplotpy-X.Y.Z Development project for development toward the next official release
• Iterate until the reviewer(s) accept and merge your changes.
• Delete your fork or branch.
• Close this issue.