CompatHelper: bump compat for "Missings" to "1.0"

[github-actions]

This pull request changes the compat entry for the Missings package from 0.4 to 0.4, 1.0.

This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry. It is your responsibility to make sure that your package tests pass before you merge this pull request.

[coveralls]

Pull Request Test Coverage Report for Build 772912746

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+6.0%) to 86.575%

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Totals
Change from base Build 756304336:	6.0%
Covered Lines:	503
Relevant Lines:	581

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💛 - Coveralls

[codecov-commenter]

Codecov Report

Merging #39 (aee0677) into dev (756a4db) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev      #39   +/-   ##
=======================================
  Coverage   80.73%   80.73%           
=======================================
  Files          15       15           
  Lines         623      623           
=======================================
  Hits          503      503           
  Misses        120      120           

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