Fix warnings

[xuwei-k]

[warn] -- Warning: /home/runner/work/cachecontrol/cachecontrol/src/main/scala/org/playframework/cachecontrol/VaryParser.scala:15:54 
[warn] 15 |      val headerNames = fieldValue.split(",\\s*").map(HeaderName)
[warn]    |                                                      ^^^^^^^^^^
[warn]    |The method `apply` is inserted. The auto insertion will be deprecated, please write `org.playframework.cachecontrol.HeaderName.apply` explicitly.
[warn] -- Deprecation Warning: /home/runner/work/cachecontrol/cachecontrol/src/main/scala/org/playframework/cachecontrol/WarningParser.scala:36:45 
[warn] 36 |    val warnText = stringLiteral ^^ { s => s.replaceAllLiterally('"'.toString, "") }
[warn]    |                                           ^^^^^^^^^^^^^^^^^^^^^
[warn]    |method replaceAllLiterally in class StringOps is deprecated since 2.13.2: Use `s.replace` as an exact replacement
[warn] -- Deprecation Warning: /home/runner/work/cachecontrol/cachecontrol/src/main/scala/org/playframework/cachecontrol/WarningParser.scala:40:22 
[warn] 40 |        val chomp = s.replaceAllLiterally('"'.toString, "")
[warn]    |                    ^^^^^^^^^^^^^^^^^^^^^
[warn]    |method replaceAllLiterally in class StringOps is deprecated since 2.13.2: Use `s.replace` as an exact replacement