Merge pull request #204 from scipp/dependabot/pip/requirements/scipp-25.4.0

Bump scipp from 25.3.0 to 25.4.0 in /requirements

Author: MridulS

requirements/base.txt

@@ -139,7 +139,7 @@ sciline==24.10.0
     # via
     #   -r base.in
     #   essreduce
-scipp==25.3.0
+scipp==25.4.0
     # via
     #   -r base.in
     #   essreduce