Fix typos in some deserialization error messages

[neilmayhew]

Changelog

- description: |
    Fix typos in some deserialization error messages
  type:
  - bugfix

Context

"Enable" and "Unable" are phonetically very similar but have widely differing meanings.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• The change log section in the PR description has been filled in
• New tests are added if needed and existing tests are updated. These may include:
  • golden tests
  • property tests
  • round trip tests
  • integration tests
    See Running tests for more details
• The version bounds in .cabal files are updated
• CI passes. See note on CI. The following CI checks are required:
  • Code is linted with hlint. See .github/workflows/check-hlint.yml to get the hlint version
  • Code is formatted with stylish-haskell. See .github/workflows/stylish-haskell.yml to get the stylish-haskell version
  • Code builds on Linux, MacOS and Windows for ghc-8.10.7 and ghc-9.2.7
• The changelog section in the PR is updated to describe the change
• Self-reviewed the diff

[smelc]

@neilmayhew> can you sign your commit?

[neilmayhew]

@neilmayhew> can you sign your commit?

It is signed, actually, and my email is one of the IDs in my GPG key. I'm not sure why GitHub thinks the signature doesn't match. Perhaps I need to re-upload my key to my GitHub profile.

[neilmayhew]

Yes, that was it. I needed to delete and re-upload my GPG key because the previous copy didn't include my email address as an ID.

[neilmayhew]

I think auto-merge isn't smart enough to notice that my commit is now verified, so this will probably need to be merged manually.