internal/mod/internal/par: move from internal/mod/mvs/internal/par

We want to be able to use this package elsewhere in the mod
packages, not just inside `mvs`.

Signed-off-by: Roger Peppe <[email protected]>
Change-Id: I13795024bbb4a39f1ebff86b4084045c95b2d608
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1172861
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Daniel Martí <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: rogpeppe

internal/mod/mvs/internal/par/queue.go internal/mod/internal/par/queue.go

@@ -12,7 +12,7 @@ import (
 	"sort"
 	"sync"
 
-	"cuelang.org/go/internal/mod/mvs/internal/par"
+	"cuelang.org/go/internal/mod/internal/par"
 )
 
 // A Reqs is the requirement graph on which Minimal Version Selection (MVS) operates.