Bump blinker from 1.7.0 to 1.8.1

Bumps [blinker](https://github.com/pallets-eco/blinker) from 1.7.0 to 1.8.1.
- [Release notes](https://github.com/pallets-eco/blinker/releases)
- [Changelog](https://github.com/pallets-eco/blinker/blob/main/CHANGES.rst)
- [Commits](pallets-eco/blinker@1.7.0...1.8.1)

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

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

backend/requirements.txt

@@ -1,5 +1,5 @@
 beautifulsoup4==4.12.3
-blinker==1.7.0
+blinker==1.8.1
 bs4==0.0.2
 certifi==2024.2.2
 charset-normalizer==3.3.2