Create local backups of regression test log files

[dpsarmie]

Commit Queue Requirements:

• This PR addresses a relevant WM issue (if not, create an issue).
• All subcomponent pull requests (if any) have been reviewed by their code managers.
• Run the full Intel+GNU RT suite (compared to current baselines), preferably on Ursa (Derecho or Hercules are acceptable alternatives). Exceptions: documentation-only PRs, CI-only PRs, etc.
  • Commit log file w/full results from RT suite run (if applicable).
  • Verify that test_changes.list indicates which tests, if any, are changed by this PR. Commit test_changes.list, even if it is empty.
• Fill out all sections of this template.

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Description:

This PR modifies rt.sh to save a backup of the most recent regression test logs. This was a requested feature that can help users when they need to run multiple tests or if they accidentally spin off a test when it was not intended. The new backup files (added extension of .bak) will not be saved to the repository and the files have been added to .gitignore

Commit Message:

* UFSWM - Add capability to create regression test log backups

Priority:

• Normal

Git Tracking

UFSWM:

• Closes Make a backup of previous RT log file before deleting #3188

Sub component Pull Requests:

• None

UFSWM Blocking Dependencies:

• None

Documentation:

• Documentation update NOT required.

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Changes

Regression Test Changes (Please commit test_changes.list):

• No Baseline Changes.

Input data Changes:

• None.

Library Changes/Upgrades:

• No Updates

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Testing Log:

• RDHPCS
  • Orion
  • Hercules
  • GaeaC6
  • Derecho
  • Ursa
• WCOSS2
  • Dogwood/Cactus
  • Acorn
• CI
• opnReqTest (complete task if unnecessary)

[gspetro-NOAA]

Merged via #3196 .