Fix a few typos found by codespell (#3543)

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## Summary

Just fix typos.

While `alpha-numeric` is not really a misspelling:
- it is missing from mainstream curated dictionaries, all of them
suggest `alphanumeric`;
- it is less used than `alphanumeric` (more than ⨉10 less) according to
the Google [Ngram
Viewer](https://books.google.com/ngrams/graph?content=alpha-numeric%2Calphanumeric&year_start=1900&year_end=2019&corpus=en-2019);
- it is [missing from
SCOWL](http://app.aspell.net/lookup?dict=en_US-large;words=alpha-numeric).

## Test Plan

CI jobs.

crates/uv-git/src/git.rs

@@ -947,7 +947,7 @@ pub(crate) fn with_fetch_options(
 
 /// Attempts to fetch the given git `reference` for a Git repository.
 ///
-/// This is the main entry for git clone/fetch. It does the followings:
+/// This is the main entry for git clone/fetch. It does the following:
 ///
 /// * Turns [`GitReference`] into refspecs accordingly.
 /// * Dispatches `git fetch` using libgit2 or git CLI.