build(deps): Bump taskcluster from 25.3.0 to 25.4.0 in /tools (#434)

Bumps [taskcluster](https://github.com/taskcluster/taskcluster) from 25.3.0 to 25.4.0.
- [Release notes](https://github.com/taskcluster/taskcluster/releases)
- [Changelog](https://github.com/taskcluster/taskcluster/blob/master/CHANGELOG.md)
- [Commits](taskcluster/taskcluster@v25.3.0...v25.4.0)

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

Author: dependabot-preview[bot]

tools/requirements.txt

@@ -3,4 +3,4 @@ async-timeout==3.0.1
 logbook==1.5.3
 raven==6.10.0
 structlog==20.1.0
-taskcluster==25.3.0
+taskcluster==25.4.0