Update sbt-scalafmt to 2.6.0

Author: usommerl-scala-steward[bot]

project/plugins.sbt

@@ -4,6 +4,6 @@ addSbtPlugin("com.eed3si9n"      % "sbt-assembly"        % "2.3.1")
 addSbtPlugin("com.eed3si9n"      % "sbt-buildinfo"       % "0.13.1")
 addSbtPlugin("com.github.sbt"    % "sbt-native-packager" % "1.11.7")
 addSbtPlugin("org.typelevel"     % "sbt-tpolecat"        % "0.5.3")
-addSbtPlugin("org.scalameta"     % "sbt-scalafmt"        % "2.5.6")
+addSbtPlugin("org.scalameta"     % "sbt-scalafmt"        % "2.6.0")
 addSbtPlugin("org.scoverage"     % "sbt-scoverage"       % "2.4.4")
 addSbtPlugin("se.marcuslonnberg" % "sbt-docker"          % "1.11.0")