Update E0023 to the new format

[pcn]

Added some extra code to check for the appropriate ending for numbers ==
1 vs. not 1 in error messages.

Added an extra test so that the plural suffix is seen and exercised.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @nrc (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see the contribution instructions for more information.

[pcn]

This is for #35196

[sophiajt]

Looks good.

@bors r+ rollup

[bors]

📌 Commit 2c563c6 has been approved by jonathandturner

[bors]

⌛ Testing commit 2c563c6 with merge 9960ad7...

[bors]

💔 Test failed - auto-win-gnu-64-opt

[alexcrichton]

@bors: retry

• not sure why...

[pcn]

The two compile-failed warnings don't appear to be related to this PR :person_frowning:

[sophiajt]

@pcn - the build bots were down yesterday morning. If you click on the compile link instead of the warnings, you can see a bunch of llvm errors. Not sure why it happened, but they seem to be working now.