Remove all usage of distutils as it is now deprecated

[Cadair]

Description

Fixes #

[dstansby]

I'm guessing this is worth backporting? It does introduce a new runtime dependency though...

[Cadair]

We could get away without backporting it, but it's probably a good idea. It should be noted that astropy has also introduced this runtime dep as well.

[dstansby]

Should probably add a changelog to notify users of the new dependency, even if it is likely that they already have it installed.

I added a changelog.

[nabobalis]

Changelog has been added.

[sunpy-backport]

The backport to 3.0 failed:

Commits ["c621050b49f220ca7baeca8a1d7bd0c2e32217d4","9868e343a3a39aea6046e67b7fdef68bd499c99d"] could not be cherry-picked on top of 3.0

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub.
git fetch
# Create new working tree.
git worktree add .worktrees/backport 3.0
# Navigate to the new directory.
cd .worktrees/backport
# Cherry-pick all the commits of this pull request and resolve the likely conflicts.
git cherry-pick c621050b49f220ca7baeca8a1d7bd0c2e32217d4 9868e343a3a39aea6046e67b7fdef68bd499c99d
# Create a new branch with these backported commits.
git checkout -b backport-5713-to-3.0
# Push it to GitHub.
git push --set-upstream origin backport-5713-to-3.0
# Go back to the original working tree.
cd ../..
# Delete the working tree.
git worktree remove .worktrees/backport

Then, create a pull request where the base branch is 3.0 and the compare/head branch is backport-5713-to-3.0.

[nabobalis]

Backported to 3.0 manually.