Bump soupsieve from 2.5 to 2.6

Bumps [soupsieve](https://github.com/facelessuser/soupsieve) from 2.5 to 2.6.
- [Release notes](https://github.com/facelessuser/soupsieve/releases)
- [Commits](facelessuser/soupsieve@2.5...2.6)

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

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

requirements.txt

@@ -12,4 +12,4 @@ requests-futures==1.0.1 # used in http.py to be able to make async HTTP requests
 requests-cache==1.2.1 # used in http.py to be able to cache HTTP requests
 ruamel.yaml==0.18.6 # used in latest.py
 ruamel.yaml.clib==0.2.8 # used in latest.py
-soupsieve==2.5 # used in conjunction with beautifulsoup4
+soupsieve==2.6 # used in conjunction with beautifulsoup4