Do not create the directories ".bsp" and ".scala-build" when launching a JAR

[spacebanana420]

Is your feature request related to a problem? Please describe.

scala-cli will become the new "scala" tool soon, and so I will use it in place of the current tool. I occasionally launch lightweight JARs either created by scalac or by scala-cli with the library package format. This allows me to not have to run an assembly JAR or a self-executable JAR. However, when using scala-cli to run these JARs, the hidden directories ".bsp" and ".scala-build" are created in the current directory.

Describe the solution you'd like

• When launching JARs with scala-cli directly, do not create the directories ".bsp" and ".scala-build" to lower clutter, if possible.

[Gedochao]

I don't think we can skip creating .scala-build, as that's where bloop files / compiler output files go, among other things... maybe in certain circumstances we could skip it, but I'd rather not for consistent behaviour. I guess we could skip .bsp if we don't have inputs other than jars and they were passed explicitly instead of through their parent directory, as there's nothing to import to the IDE then.