fix: upgrade mailsuite requirement to >=2.3.2 for Python 3.14 support (closes #838)

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ### Changes
 
+- Upgrade the `mailsuite` requirement to `>=2.3.2`, which sets the `IMAPClient` version to `>=4.0.0`, fixing support for Python 3.14 (Closes #838)
+
 - **The prebuilt Docker image (`ghcr.io/domainaware/parsedmarc`) is roughly 40% smaller to pull** ([#893](https://github.com/domainaware/parsedmarc/pull/893)). The runtime stage copied the built wheel out of the build stage and deleted it again at the end of the next `RUN`, but a `RUN` can only write a whiteout over a layer an earlier instruction already committed: the wheel shipped in every published image and every `docker pull` downloaded it (10,713,473 bytes of the 11.0.0 image, on both architectures). The wheel is now bind-mounted from the build stage instead, and a bind mount is never committed to a layer. `pip install` also runs with `--no-cache-dir`, which drops a further ~99 MB of pip's download cache that the image had been carrying in the same layer as `site-packages`. Measured on linux/amd64: 272,138,724 compressed bytes across six layers before, 163,757,439 across five after.
 - **Bare `exit(...)` calls are now `sys.exit(...)` throughout the CLI and the maintainer map-tooling scripts.** `exit` is installed into `builtins` by the `site` module, not just for interactive sessions, so it isn't guaranteed to exist under `python -S` or an embedded interpreter that skips `site` — the failure paths that called it would raise `NameError` instead of actually exiting. `sys.exit` is always available and was already used elsewhere in `cli.py` and `find_unknown_base_reverse_dns.py`. Also removed the dead, immediately-recomputed `index_date` stores in the Elasticsearch and OpenSearch aggregate-report savers; behavior is unchanged.
 

pyproject.toml

@@ -56,7 +56,7 @@ dependencies = [
     # No extras: the base mailsuite supplies IMAP and Maildir connections
     # plus mail-parser. Gmail and Microsoft Graph come from the gmail and
     # msgraph extras below.
-    "mailsuite>=2.3.1",
+    "mailsuite>=2.3.2",
     "maxminddb>=2.0.0",
     "publicsuffixlist>=0.10.0",
     # Imported directly at utils.py:39 (dateutil.parser). It used to