Ignore legislation_process nesting in stylelint

This file was generated by a different developer who ignored the nesting
rules. Refactoring it has been in our TODO list for years, but we
haven't done it yet.

Since we want stylelint to check that there are no errors after the
changes in a pull request, but we've still got errors in this file,
we're ignoring them for now.

.stylelintrc.yml

@@ -89,3 +89,8 @@ rules:
   "@stylistic/color-hex-case": "lower"
   "@stylistic/number-leading-zero": "always"
   "@stylistic/selector-list-comma-newline-after": always
+overrides:
+  - files: app/assets/stylesheets/legislation_process.scss
+    rules:
+      max-nesting-depth: 8
+      selector-max-compound-selectors: 8