Disable the loop-iterator-mutation rule in ruff

[correctmost]

PR Description:

This allows ruff check --preview to succeed again.

Here's the warning that is now suppressed:

archinstall/lib/pacman/config.py:46:6: B909 Mutation to loop iterable `content` during iteration
   |
44 |                 # also uncomment the next line (Include statement) if it exists and is commented
45 |                 if row + 1 < len(content) and content[row + 1].lstrip().startswith('#'):
46 |                     content[row + 1] = re.sub(r'^#\s*', '', content[row + 1])
   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ B909
47 |
48 |         # Write the modified content back to the file
   |

Found 1 error.

[codefiles]

Why not fix it rather than suppress it? Would this be preferable?

diff --git a/archinstall/lib/pacman/config.py b/archinstall/lib/pacman/config.py
index 6ea75d4e..948db2de 100644
--- a/archinstall/lib/pacman/config.py
+++ b/archinstall/lib/pacman/config.py
@@ -33,7 +33,10 @@ class PacmanConfig:

                content = self._config_path.read_text().splitlines(keepends=True)

-               for row, line in enumerate(content):
+               row = 0
+               while row < len(content):
+                       line = content[row]
+
                        # Check if this is a commented repository section that needs to be enabled
                        match = re.match(r'^#\s*\[(.*)\]', line)

@@ -44,6 +47,9 @@ class PacmanConfig:
                                # also uncomment the next line (Include statement) if it exists and is commented
                                if row + 1 < len(content) and content[row + 1].lstrip().startswith('#'):
                                        content[row + 1] = re.sub(r'^#\s*', '', content[row + 1])
+                                       row += 1
+
+                       row += 1

                # Write the modified content back to the file
                with open(self._config_path, 'w') as f:

This also enables skipping content[row + 1] after substitution has been performed on it.

[correctmost]

Why not fix it rather than suppress it? Would this be preferable?

I opted to disable the rule for now because a similar redefined-loop-name rule (PLW2901) is disabled. Some of the loop-iterator-mutation violations strike me as stylistic in nature, so I also didn't want to impose a style on the codebase when it wouldn't have a clear impact on correctness or performance.

In the long run, I would like most of the current exclusions to be re-enabled because I think they can eventually help catch more issues. In the short term, I am mainly trying to keep ruff check --preview passing to avoid build breakage from ruff's frequent releases.

The proposed patch looks good, but some people may find it a bit harder to read because of the double increment. Manual increments can also lead to infinite loops if continue statements get added later on. This is why I think the rule is a bit stylistic and opted to disable it :).