bump our own version

Author: SethTisue

README.md

@@ -17,7 +17,7 @@ Only the most commonly used APIs are supported; many are missing. Contributions
 To use this library, add the following to your `build.sbt`:
 
 ```
-libraryDependencies += "org.scala-lang.modules" %% "scala-collection-compat" % "2.3.2"
+libraryDependencies += "org.scala-lang.modules" %% "scala-collection-compat" % "2.4.0"
 ```
 
 All future versions will remain backwards binary compatible with 2.0.0. (The 1.0.0 release was withdrawn and should not be used.)
@@ -64,7 +64,7 @@ The `Collection213Upgrade` rewrite upgrades to the 2.13 collections without the
 
 ```scala
 // build.sbt
-scalafixDependencies in ThisBuild += "org.scala-lang.modules" %% "scala-collection-migrations" % "2.3.2"
+scalafixDependencies in ThisBuild += "org.scala-lang.modules" %% "scala-collection-migrations" % "2.4.0"
 addCompilerPlugin(scalafixSemanticdb)
 scalacOptions ++= List("-Yrangepos", "-P:semanticdb:synthetics:on")
 ```
@@ -82,8 +82,8 @@ To cross-build for 2.12 and 2.11, the rewrite rule introduces a dependency on th
 
 ```scala
 // build.sbt
-scalafixDependencies in ThisBuild += "org.scala-lang.modules" %% "scala-collection-migrations" % "2.3.1"
-libraryDependencies +=  "org.scala-lang.modules" %% "scala-collection-compat" % "2.3.2"
+scalafixDependencies in ThisBuild += "org.scala-lang.modules" %% "scala-collection-migrations" % "2.4.0"
+libraryDependencies +=  "org.scala-lang.modules" %% "scala-collection-compat" % "2.4.0"
 addCompilerPlugin(scalafixSemanticdb)
 scalacOptions ++= List("-Yrangepos", "-P:semanticdb:synthetics:on")
 ```

build.sbt

@@ -74,7 +74,7 @@ lazy val compat = MultiScalaCrossProject(JSPlatform, JVMPlatform, NativePlatform
     .jvmSettings(
       Test / unmanagedSourceDirectories += (ThisBuild / baseDirectory).value / "compat/src/test/scala-jvm",
       junit,
-      scalaModuleMimaPreviousVersion := Some("2.3.0").filterNot(_ => isDotty.value),
+      scalaModuleMimaPreviousVersion := Some("2.4.0").filterNot(_ => isDotty.value),
       mimaBinaryIssueFilters ++= {
         import com.typesafe.tools.mima.core._
         import com.typesafe.tools.mima.core.ProblemFilters._