Make Context.current a transparent inline to make it work under Scala 3.4.+

[WojciechMazur]

It fixes compilation, and possibly usage for users of the Context.current due to scala/scala3#19253
Issue spotted by Scala 3 Open Community Build - logs
Since 3.4.0 it would fail with:

[error] -- [E172] Type Error: /Users/wmazur/projects/community-build3/repo/ducktape/src/main/scala/io/github/arainko/ducktape/internal/Planner.scala:274:32 
[error] 274 |          ctx.reifyPlan[F](plan)
[error]     |                                ^
[error]     |Cannot prove that io.github.arainko.ducktape.internal.Plan[
[error]     |  io.github.arainko.ducktape.internal.Erroneous, ctx.F] =:= io.github.arainko.ducktape.internal.Plan[
[error]     |  io.github.arainko.ducktape.internal.Erroneous, F²].
[error]     |
[error]     |where:    F  is a type in class PossiblyFallible which is an alias of io.github.arainko.ducktape.internal.Fallible
[error]     |          F² is a type in method unapply with bounds <: io.github.arainko.ducktape.internal.Fallible
[error] -- [E172] Type Error: /Users/wmazur/projects/community-build3/repo/ducktape/src/main/scala/io/github/arainko/ducktape/internal/Planner.scala:296:11 
[error] 296 |          }
[error]     |           ^
[error]     |Cannot prove that io.github.arainko.ducktape.internal.Plan[
[error]     |  io.github.arainko.ducktape.internal.Erroneous, ctx.F] =:= io.github.arainko.ducktape.internal.Plan[
[error]     |  io.github.arainko.ducktape.internal.Erroneous, F²].
[error]     |
[error]     |where:    F  is a type in class PossiblyFallible which is an alias of io.github.arainko.ducktape.internal.Fallible
[error]     |          F² is a type in method unapply with bounds <: io.github.arainko.ducktape.internal.Fallible
[error] -- [E172] Type Error: /Users/wmazur/projects/community-build3/repo/ducktape/src/main/scala/io/github/arainko/ducktape/internal/Planner.scala:315:11 
[error] 315 |          }
[error]     |           ^
[error]     |Cannot prove that io.github.arainko.ducktape.internal.Plan[
[error]     |  io.github.arainko.ducktape.internal.Erroneous, ctx.F] =:= io.github.arainko.ducktape.internal.Plan[
[error]     |  io.github.arainko.ducktape.internal.Erroneous, F²].
[error]     |
[error]     |where:    F  is a type in class PossiblyFallible which is an alias of io.github.arainko.ducktape.internal.Fallible
[error]     |          F² is a type in method unapply with bounds <: io.github.arainko.ducktape.internal.Fallible

The constraint might be also applicable for other current methods used to summon implicit, eg. Mode.current but I've not spotted any problems with it so far

[arainko]

Awesome, thank you! ❤️