CreateOrMergeNixConfig: don't error when mode is different

When we write out the new or merged config, we'll set it to our expected
mode anyways, so there's no need to error if it's different.

src/action/base/create_or_merge_nix_config.rs

@@ -147,19 +147,6 @@ impl CreateOrMergeNixConfig {
             return Err(Self::error(ActionErrorKind::PathWasNotFile(path)));
         }
 
-        // Does the file have the right permissions?
-        let discovered_mode = metadata.permissions().mode();
-        // We only care about user-group-other permissions
-        let discovered_mode = discovered_mode & 0o777;
-
-        if discovered_mode != NIX_CONF_MODE {
-            return Err(Self::error(ActionErrorKind::PathModeMismatch(
-                path,
-                discovered_mode,
-                NIX_CONF_MODE,
-            )));
-        }
-
         let existing_nix_config = NixConfig::parse_file(&path)
             .map_err(CreateOrMergeNixConfigError::ParseNixConfig)
             .map_err(Self::error)?;