Update twisted requirement from >=25.5.0 to >=26.4.0rc2

Updates the requirements on [twisted](https://github.com/twisted/twisted) to permit the latest version.
- [Release notes](https://github.com/twisted/twisted/releases)
- [Changelog](https://github.com/twisted/twisted/blob/trunk/NEWS.rst)
- [Commits](twisted/twisted@twisted-25.5.0...twisted-26.4.0rc2)

---
updated-dependencies:
- dependency-name: twisted
  dependency-version: 26.4.0rc2
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements/base.txt

@@ -31,7 +31,7 @@ pgvector>=0.4.0  # Python binding for pgvector; PostgreSQL extension v0.8.2+ req
 channels==4.3.2  # https://github.com/django/channels
 daphne==4.2.1  # https://github.com/django/daphne
 channels-redis==4.3.0
-Twisted[tls,http2]>=25.5.0
+Twisted[tls,http2]>=26.4.0rc2
 
 # Django REST Framework
 # ------------------------------------------------------------------------------

requirements/local.txt

@@ -52,7 +52,7 @@ python-pptx
 # Not directly required, pinned by Snyk to avoid a vulnerability
 # ------------------------------------------------------------------------------
 django==5.2.13  # https://www.djangoproject.com/
-twisted>=25.5.0 # not directly required, pinned by Snyk to avoid a vulnerability
+twisted>=26.4.0rc2 # not directly required, pinned by Snyk to avoid a vulnerability
 ipython>=9.13.0 # not directly required, pinned by Snyk to avoid a vulnerability
 requests>=2.33.1,<3 # not directly required, pinned by Snyk to avoid a vulnerability
 setuptools>=82.0.1 # not directly required, pinned by Snyk to avoid a vulnerability

requirements/production.txt

@@ -18,7 +18,7 @@ google-auth==2.49.2
 # Duplicated accross requirements files due to Snyk not understanding requirements inheritance
 # ------------------------------------------------------------------------------
 django==5.2.13  # https://www.djangoproject.com/
-twisted>=25.5.0 # not directly required, pinned by Snyk to avoid a vulnerability
+twisted>=26.4.0rc2 # not directly required, pinned by Snyk to avoid a vulnerability
 ipython>=9.13.0 # not directly required, pinned by Snyk to avoid a vulnerability
 requests>=2.33.1,<3 # not directly required, pinned by Snyk to avoid a vulnerability
 setuptools>=82.0.1 # not directly required, pinned by Snyk to avoid a vulnerability