Bump sphinxcontrib-towncrier from 0.3.2a0 to 0.4.0a0

Bumps [sphinxcontrib-towncrier](https://github.com/sphinx-contrib/sphinxcontrib-towncrier) from 0.3.2a0 to 0.4.0a0.
- [Release notes](https://github.com/sphinx-contrib/sphinxcontrib-towncrier/releases)
- [Commits](sphinx-contrib/sphinxcontrib-towncrier@v0.3.2a0...v0.4.0a0)

---
updated-dependencies:
- dependency-name: sphinxcontrib-towncrier
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docs/requirements.txt

@@ -262,9 +262,9 @@ sphinxcontrib-serializinghtml==1.1.5 \
     --hash=sha256:352a9a00ae864471d3a7ead8d7d79f5fc0b57e8b3f95e9867eb9eb28999b92fd \
     --hash=sha256:aa5f6de5dfdf809ef505c4895e51ef5c9eac17d0f287933eb49ec495280b6952
     # via sphinx
-sphinxcontrib-towncrier==0.3.2a0 \
-    --hash=sha256:74fc27a24231b56f1e4820a5dcb121a8c69aa6b6a0d2367c61144b9673ebf73a \
-    --hash=sha256:7cf18ac9c13533fffdb794dab278c6ad845f8c85bfa56942eba077d543885fa6
+sphinxcontrib-towncrier==0.4.0a0 \
+    --hash=sha256:d9b1513fc07781432dd3a0b2ca797cfe0e99e9b5bc5e5c8bf112d5d142afb6dc \
+    --hash=sha256:ec734e3d0920e2ce26e99681119f398a9e1fc0aa6c2d7ed1f052f1219dcd4653
     # via -r docs/requirements.in
 tomli==1.2.2 \
     --hash=sha256:c6ce0015eb38820eaf32b5db832dbc26deb3dd427bd5f6556cf0acac2c214fee \