Use 'dmypy run' in lint.sh instead of 'mypy' (#9701)

For it's obvious performance benefits. `dmypy` support landed in #9692.

changelog.d/9701.misc

+Use `dmypy run` in lint script for improved performance in type-checking while developing.
\ No newline at end of file

scripts-dev/lint.sh

@@ -95,4 +95,4 @@ isort "${files[@]}"
 python3 -m black "${files[@]}"
 ./scripts-dev/config-lint.sh
 flake8 "${files[@]}"
-mypy
+dmypy run