refactor: Use runeio library.

[ianlewis]

The runes package was externalized in the runeio module. Use that as a dependency.

Description:

The generic runes package can be better maintained as a separate module.

Related Issues:

Fixes #973

Checklist:

• Review the CONTRIBUTING.md documentation.
• Add a reference to a related issue in the repository.
• Add a description of the changes proposed in the pull request.
• Add unit tests if applicable.
• Add a note in the CHANGELOG.md if applicable.
• Sign the Google CLA.

[codecov]

Codecov Report

Merging #992 (b817cf2) into main (146d57d) will decrease coverage by 0.54%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #992      +/-   ##
==========================================
- Coverage   82.14%   81.61%   -0.54%     
==========================================
  Files          19       18       -1     
  Lines        1126     1050      -76     
  Branches       14       14              
==========================================
- Hits          925      857      -68     
+ Misses        146      140       -6     
+ Partials       55       53       -2     

Files	Coverage Δ
internal/scanner/scanner.go	78.15% <100.00%> (ø)