ruff: Configure hacking as external linter

Change-Id: Ib8efb96bb066a3b981ca236b379003c2b151ca7d
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

pyproject.toml

@@ -48,7 +48,7 @@ show_column_numbers = true
 show_error_context = true
 strict = true
 disable_error_code = ["import-untyped"]
-exclude = '(?x)(doc | releasenotes)'
+exclude = "(?x)(doc | releasenotes)"
 
 [tool.ruff]
 line-length = 79
@@ -59,3 +59,4 @@ docstring-code-format = true
 
 [tool.ruff.lint]
 select = ["E4", "E5", "E7", "E9", "F", "G", "LOG", "UP"]
+external = ["H"]