chore: Add #2195 to git blame ignore list (#2199)

Prevents the noisy automated changes of #2195 from polluting the blame
history.

This needs local configuration to be picked up by git:
```bash
git config blame.ignoreRevsFile .git-blame-ignore-revs
```

But it's [automatically read by
github](https://docs.github.com/en/repositories/working-with-files/using-files/viewing-and-understanding-files#ignore-commits-in-the-blame-view).

Author: aborgna-q

.git-blame-ignore-revs

@@ -0,0 +1,8 @@
+# Commits to ignore in blame output
+#
+# To configure git to use this file, run:
+# > git config blame.ignoreRevsFile .git-blame-ignore-revs
+
+# Bump to rust edition 2024, and a bunch of automated lint fixes
+# https://github.com/CQCL/hugr/pull/2195
+16903a65294aede245a4c8bb2a07a4692a619769