Bump pyramid-tm from 2.3 to 2.4

Bumps [pyramid-tm](https://github.com/Pylons/pyramid_tm) from 2.3 to 2.4.
- [Release notes](https://github.com/Pylons/pyramid_tm/releases)
- [Changelog](https://github.com/Pylons/pyramid_tm/blob/master/CHANGES.rst)
- [Commits](Pylons/pyramid_tm@2.3...2.4)

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

requirements.txt

@@ -28,7 +28,7 @@ pycparser==2.19
 PyFxA==0.7.3
 pyramid==1.10.4
 pyramid-multiauth==0.9.0
-pyramid-tm==2.3
+pyramid-tm==2.4
 python-dateutil==2.8.1
 repoze.lru==0.7
 requests==2.22.0