Bump pyqt5-qt5 from 5.15.2 to 5.15.12 in /envs

Bumps [pyqt5-qt5](https://www.riverbankcomputing.com/software/pyqt/) from 5.15.2 to 5.15.12.

---
updated-dependencies:
- dependency-name: pyqt5-qt5
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

envs/requirements.txt

@@ -40,7 +40,7 @@ pyface==8.0.0
 Pygments==2.16.1
 pyparsing==3.1.1
 PyQt5==5.15.10
-PyQt5-Qt5==5.15.2
+PyQt5-Qt5==5.15.12
 PyQt5-sip==12.13.0
 python-bioformats==4.0.7.post5+g52309d1
 python-dateutil==2.8.2