Fix autoplot.epi_archive on archives with a v column

[brookslogan]

Checklist

Please:

• Make sure this PR is against "dev", not "main" (unless this is a release
  PR).
• Request a review from one of the current main reviewers:
  brookslogan, nmdefries.
• Makes sure to bump the version number in DESCRIPTION. Always increment
  the patch version number (the third number), unless you are making a
  release PR from dev to main, in which case increment the minor version
  number (the second number).
• Describe changes made in NEWS.md, making sure breaking changes
  (backwards-incompatible changes to the documented interface) are noted.
  Collect the changes under the next release number (e.g. if you are on
  1.7.2, then write your changes under the 1.8 heading).
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• See DEVELOPMENT.md for more information on the development
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Change explanations for reviewer

• Uses .env$v to avoid using v column.
• Also changing to a .9999 dev version numbering scheme.

Magic GitHub syntax to mark associated Issue(s) as resolved when this is merged into the default branch

• Resolves autoplot.epi_archive fails when there is a pre-existing column named v #674.

[brookslogan]

/style

[brookslogan]

/document

[brookslogan]

/preview-docs

[github-actions]

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