reproducible builds: inner functions are not consistently generated on Scala 3

reproducing 1.1.0-M1 with `set ThisBuild / net.bzzt.reproduciblebuilds.ReproducibleBuildsPlugin.reproducibleBuildsCheckResolver := DefaultMavenRepository; ++3.3; clean; reproducibleBuildsCheck` showed two nondeterminisms for me in pekko-http_3-1.1.0-M1.jar :

* In org/apache/pekko/http/scaladsl/server/directives/FileUploadDirectives.class, one build had `default·Directive·storeUploadedFile$$anonfun$1$(final·FileUploadDirectives·$this,·final·String·fieldName$1,·final·Function1·destFn$1,·final·RequestContext·ctx)` and `default·/*·synthetic·*/·Directive·storeUploadedFile$$anonfun$1(final·String·fieldName$1,·final·Function1·destFn$1,·final·RequestContext·ctx)`, the other hadn't
* In org/apache/pekko/http/scaladsl/server/directives/RangeDirectives.class, one build didn't have `default·Directive·applyRanges$1$(final·RangeDirectives·$this,·final·LoggingAdapter·log$3,·final·RoutingSettings·settings$6,·final·Seq·ranges)`, the other did.

Note `default·Directive·storeUploadedFile$$anonfun$1$(final·FileUploadDirectives·$this,·final·String·fieldName$1,·final·Function1·destFn$1,·final·RequestContext·ctx)` is a function with an actual implementation - if that's not there, does it even work? Or is it duplicated somewhere?

Possibly related to https://github.com/scala/scala3/issues/18248