Log Message:
devel/difftastic: update to 0.48.0

0.48 (released 12th July 2023)
Parsing
 - Updated Scala parser.
 - Improved parsing of qualified modules and variables in Haskell.

Diffing
 - Replaced strings now have subword highlighting, consistent with replaced
   comments. Thanks @amnore!
 - Fixed an issue with the cost model for comment replacement, leading
   difftastic to prefer modified comments even when exact comment matches are
   possible.
 - Simplified the cost model, which previously had an inconsistent heuristic
   depending on whether there were multiple items on the same line. This can
   lead to slightly different items being marked as changed, but on average the
   results are better.

Display
 - Improved word highlighting in comments when they contain numbers or hyphens.

Internals
 - Difftastic's logging is now configured with the environment variable DFT_LOG.
   This was previously RUST_LOG, which could interfere with users configuring
   logging for their own development work.