Bump pip-tools from 5.3.1 to 5.4.0

Bumps [pip-tools](https://github.com/jazzband/pip-tools) from 5.3.1 to 5.4.0.
- [Release notes](https://github.com/jazzband/pip-tools/releases)
- [Changelog](https://github.com/jazzband/pip-tools/blob/master/CHANGELOG.md)
- [Commits](jazzband/pip-tools@5.3.1...5.4.0)

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

requirements/dev.txt

@@ -27,7 +27,7 @@ mypy==0.790               # via -r requirements/dev.in
 nodeenv==1.3.5            # via pre-commit
 packaging==20.3           # via pallets-sphinx-themes, pytest, sphinx, tox
 pallets-sphinx-themes==1.2.3  # via -r requirements/docs.in
-pip-tools==5.3.1          # via -r requirements/dev.in
+pip-tools==5.4.0          # via -r requirements/dev.in
 pluggy==0.13.1            # via pytest, tox
 pre-commit==2.8.2         # via -r requirements/dev.in
 py==1.9.0                 # via pytest, tox