Bump pysigma-backend-splunk from 1.0.2 to 1.1.0

Bumps [pysigma-backend-splunk](https://github.com/SigmaHQ/pySigma-backend-splunk) from 1.0.2 to 1.1.0.
- [Release notes](https://github.com/SigmaHQ/pySigma-backend-splunk/releases)
- [Commits](SigmaHQ/pySigma-backend-splunk@v1.0.2...v1.1.0)

---
updated-dependencies:
- dependency-name: pysigma-backend-splunk
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements.txt

@@ -8,7 +8,7 @@ psutil==5.9.8
 pycvesearch==1.2
 pydantic==1.10.8
 pysigma==0.11.3
-pysigma-backend-splunk==1.0.2
+pysigma-backend-splunk==1.1.0
 pytest==7.4.4
 PyYAML>=5.4.1
 questionary==1.10.0