Fix exception "named capturing group is missing trailing '}'"

[fthomas]

No description provided.

[codecov]

Codecov Report

Merging #566 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master     #566   +/-   ##
=======================================
  Coverage   58.09%   58.09%           
=======================================
  Files          65       65           
  Lines         821      821           
  Branches       38       39    +1     
=======================================
  Hits          477      477           
  Misses        344      344

Impacted Files	Coverage Δ
...a/org/scalasteward/core/edit/UpdateHeuristic.scala	100% <100%> (ø)	⬆️

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