Remove tests/benchmarks JMH project

The benchmark suite is unused. Drop the bench sbt project, its
sources under tests/benchmarks, and the sbt-jmh plugin that only
existed to support it.

Author: jupblb

build.sbt

@@ -654,17 +654,6 @@ lazy val snapshots = project
   .dependsOn(unit)
   .enablePlugins(BuildInfoPlugin)
 
-lazy val bench = project
-  .in(file("tests/benchmarks"))
-  .settings(
-    moduleName := "scip-java-bench",
-    Jmh / bspEnabled := false,
-    (run / fork) := true,
-    (publish / skip) := true
-  )
-  .dependsOn(unit)
-  .enablePlugins(JmhPlugin)
-
 lazy val javaOnlySettings = List[Def.Setting[_]](
   javafmtOnCompile := false,
   autoScalaLibrary := false,

project/plugins.sbt

@@ -6,7 +6,6 @@ addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.5")
 addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.14.3")
 addSbtPlugin("com.thesamet" % "sbt-protoc" % "1.0.6")
 addSbtPlugin("com.lightbend.sbt" % "sbt-java-formatter" % "0.6.1")
-addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.4.3")
 addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.15.0")
 addSbtPlugin("org.jetbrains.scala" % "sbt-kotlin-plugin" % "3.1.6")
 addSbtPlugin("com.github.sbt.junit" % "sbt-jupiter-interface" % "0.15.1")