Update qt-range-slider requirement from ~=0.2.7 to ~=0.4.2

Updates the requirements on [qt-range-slider](https://github.com/introkun/qt-range-slider) to permit the latest version.
- [Commits](introkun/qt-range-slider@v0.2.7...v0.4.2)

---
updated-dependencies:
- dependency-name: qt-range-slider
  dependency-type: direct:production
...

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

requirements.txt

@@ -18,7 +18,7 @@ asn1~=2.4.2
 filelock~=3.4.2
 Unidecode~=1.3.2
 pycurl~=7.44.1; sys_platform != 'win32'
-qt-range-slider~=0.2.7
+qt-range-slider~=0.4.2
 watchdog~=2.1.6
 certifi>=2021.5.30
 humanize~=3.14