ci: Add Qt 5.15.0

We test Qt 5.15.2, but that's based on a newer Chromium version:

Qt 5.14.x -> Chromium 77
Qt 5.15.0 -> Chromium 80
Qt 5.15.2 -> Chromium 83

Some behavior changes between Chromium versions (see e.g. #5915), so it
makes sense to test both.

Picking 5.15.0 rather than .1 due to renderer process crashes in
5.15.1 (#5721). Doesn't matter much on the CI as we don't use WebRTC,
but if someone wants to downgrade with mkvenv.py for some reason, .0
will be more useful than .1.

.github/workflows/ci.yml

@@ -112,6 +112,10 @@ jobs:
           - testenv: py38-pyqt514
             os: ubuntu-20.04
             python: 3.8
+          ### PyQt 5.15.0 (Python 3.9)
+          - testenv: py39-pyqt5150
+            os: ubuntu-20.04
+            python: 3.9
           ### PyQt 5.15 (Python 3.9, with coverage)
           - testenv: py39-pyqt515-cov
             os: ubuntu-20.04

misc/requirements/requirements-pyqt-5.15.0.txt

@@ -0,0 +1,5 @@
+# This file is automatically generated by scripts/dev/recompile_requirements.py
+
+PyQt5==5.15.2  # rq.filter: < 6
+PyQt5-sip==12.8.1
+PyQtWebEngine==5.15.0  # rq.filter: == 5.15.0

misc/requirements/requirements-pyqt-5.15.0.txt-raw

@@ -0,0 +1,4 @@
+#@ filter: PyQt5 < 6
+#@ filter: PyQtWebEngine == 5.15.0
+PyQt5 >= 5.15, < 6
+PyQtWebEngine == 5.15.0

tox.ini

@@ -12,8 +12,8 @@ minversion = 3.15
 [testenv]
 setenv =
     PYTEST_QT_API=pyqt5
-    pyqt{,512,513,514,515}: LINK_PYQT_SKIP=true
-    pyqt{,512,513,514,515}: QUTE_BDD_WEBENGINE=true
+    pyqt{,512,513,514,515,5150}: LINK_PYQT_SKIP=true
+    pyqt{,512,513,514,515,5150}: QUTE_BDD_WEBENGINE=true
     cov: PYTEST_ADDOPTS=--cov --cov-report xml --cov-report=html --cov-report=
 passenv = PYTHON DISPLAY XAUTHORITY HOME USERNAME USER CI XDG_* QUTE_* DOCKER QT_QUICK_BACKEND PY_COLORS
 basepython =
@@ -30,6 +30,7 @@ deps =
     pyqt513: -r{toxinidir}/misc/requirements/requirements-pyqt-5.13.txt
     pyqt514: -r{toxinidir}/misc/requirements/requirements-pyqt-5.14.txt
     pyqt515: -r{toxinidir}/misc/requirements/requirements-pyqt-5.15.txt
+    pyqt5150: -r{toxinidir}/misc/requirements/requirements-pyqt-5.15.0.txt
 commands =
     {envpython} scripts/link_pyqt.py --tox {envdir}
     {envpython} -bb -m pytest {posargs:tests}