The existing code was using the `r(groupNames: String*)` extension
method on `String` to create a regex with named capturing groups, but
that Scala method was deprecated with Scala 2.13.7:

https://www.scala-lang.org/api/2.13.8/scala/collection/StringOps.html#r(groupNames:String*):scala.util.matching.Regex

The `r(groupNames: String*)` method became unnecessary as Scala adopted
Java 8 with Scala 2.12, since Java 7 introduced support for
'Named Capturing Groups' (also called 'inline group names' in related
Scala PRs):

> A capturing group can also be assigned a "name", a named-capturing
> group, and then be back-referenced later by the "name".

* https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#groupname
* https://blog.mrhaki.com/2020/04/java-joy-using-named-capturing-groups.html

The PR that deprecated the `r(groupNames: String*)` method in the
Scala standard library: scala/scala#9718 -
following on from scala/scala#4990 and
scala/bug#9666.

The existing code was using the `r(groupNames: String*)` extension
method on `String` to create a regex with named capturing groups, but
that Scala method was deprecated with Scala 2.13.7:

https://www.scala-lang.org/api/2.13.8/scala/collection/StringOps.html#r(groupNames:String*):scala.util.matching.Regex

The `r(groupNames: String*)` method became unnecessary as Scala adopted
Java 8 with Scala 2.12, since Java 7 introduced support for
'Named Capturing Groups' (also called 'inline group names' in related
Scala PRs):

> A capturing group can also be assigned a "name", a named-capturing
> group, and then be back-referenced later by the "name".

* https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#groupname
* https://blog.mrhaki.com/2020/04/java-joy-using-named-capturing-groups.html

The PR that deprecated the `r(groupNames: String*)` method in the
Scala standard library: scala/scala#9718 -
following on from scala/scala#4990 and
scala/bug#9666.