Bump scipp from 24.8.0 to 24.9.1 in /requirements

Bumps [scipp](https://github.com/scipp/scipp) from 24.8.0 to 24.9.1.
- [Release notes](https://github.com/scipp/scipp/releases)
- [Commits](scipp/scipp@24.08.0...24.09.1)

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

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

requirements/base.txt

@@ -25,8 +25,6 @@ decorator==5.1.1
     # via ipython
 essreduce==24.8.2
     # via -r base.in
-exceptiongroup==1.2.2
-    # via ipython
 executing==2.0.1
     # via stack-data
 fonttools==4.53.1
@@ -39,8 +37,6 @@ h5py==3.11.0
     # via
     #   scippneutron
     #   scippnexus
-importlib-metadata==8.4.0
-    # via dask
 ipydatawidgets==4.3.5
     # via pythreejs
 ipython==8.26.0
@@ -117,7 +113,7 @@ sciline==24.6.2
     # via
     #   -r base.in
     #   essreduce
-scipp==24.8.0
+scipp==24.9.1
     # via
     #   -r base.in
     #   essreduce
@@ -154,11 +150,7 @@ traitlets==5.14.3
     #   traittypes
 traittypes==0.2.1
     # via ipydatawidgets
-typing-extensions==4.12.2
-    # via ipython
 wcwidth==0.2.13
     # via prompt-toolkit
 widgetsnbextension==4.0.13
     # via ipywidgets
-zipp==3.20.0
-    # via importlib-metadata