Update pylint requirement from ~=2.7 to ~=2.8 (#34)

Updates the requirements on [pylint](https://github.com/PyCQA/pylint) to permit the latest version.
- [Release notes](https://github.com/PyCQA/pylint/releases)
- [Changelog](https://github.com/PyCQA/pylint/blob/master/ChangeLog)
- [Commits](pylint-dev/pylint@pylint-2.7.0...pylint-2.8.1)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

dic2owl/requirements_dev.txt

@@ -1,2 +1,2 @@
 pre-commit~=2.12
-pylint~=2.7
+pylint~=2.8