Drop redundant Pure parent traits in stdlib (#24149)

Author: hamzaremmal

library/src/scala/collection/IndexedSeq.scala

@@ -24,8 +24,7 @@ import scala.math.Ordering
 /** Base trait for indexed sequences that have efficient `apply` and `length` */
 trait IndexedSeq[+A] extends Seq[A]
   with IndexedSeqOps[A, IndexedSeq, IndexedSeq[A]]
-  with IterableFactoryDefaults[A, IndexedSeq]
-  with caps.Pure {
+  with IterableFactoryDefaults[A, IndexedSeq] {
   @nowarn("""cat=deprecation&origin=scala\.collection\.Iterable\.stringPrefix""")
   override protected[this] def stringPrefix: String = "IndexedSeq"
 

library/src/scala/collection/SeqMap.scala

@@ -32,8 +32,7 @@ import scala.annotation.nowarn
 
 trait SeqMap[K, +V] extends Map[K, V]
   with MapOps[K, V, SeqMap, SeqMap[K, V]]
-  with MapFactoryDefaults[K, V, SeqMap, Iterable]
-  with caps.Pure {
+  with MapFactoryDefaults[K, V, SeqMap, Iterable] {
   @nowarn("""cat=deprecation&origin=scala\.collection\.Iterable\.stringPrefix""")
   override protected[this] def stringPrefix: String = "SeqMap"
 

library/src/scala/collection/immutable/ArraySeq.scala

@@ -41,8 +41,7 @@ sealed abstract class ArraySeq[+A]
     with IndexedSeqOps[A, ArraySeq, ArraySeq[A]]
     with StrictOptimizedSeqOps[A, ArraySeq, ArraySeq[A]]
     with EvidenceIterableFactoryDefaults[A, ArraySeq, ClassTag]
-    with Serializable
-    with caps.Pure {
+    with Serializable{
 
   /** The tag of the element type. This does not have to be equal to the element type of this ArraySeq. A primitive
     * ArraySeq can be backed by an array of boxed values and a reference ArraySeq can be backed by an array of a supertype

library/src/scala/collection/immutable/Seq.scala

@@ -122,8 +122,7 @@ object IndexedSeq extends SeqFactory.Delegate[IndexedSeq](Vector) {
 /** Base trait for immutable indexed Seq operations */
 transparent trait IndexedSeqOps[+A, +CC[B] <: caps.Pure, +C]
   extends SeqOps[A, CC, C]
-    with collection.IndexedSeqOps[A, CC, C]
-    with caps.Pure {
+    with collection.IndexedSeqOps[A, CC, C] {
 
   override def slice(from: Int, until: Int): C = {
     // since we are immutable we can just share the same collection

library/src/scala/collection/immutable/StrictOptimizedSeqOps.scala

@@ -25,8 +25,7 @@ transparent trait StrictOptimizedSeqOps[+A, +CC[B] <: caps.Pure, +C]
   extends Any
     with SeqOps[A, CC, C]
     with collection.StrictOptimizedSeqOps[A, CC, C]
-    with StrictOptimizedIterableOps[A, CC, C]
-    with caps.Pure {
+    with StrictOptimizedIterableOps[A, CC, C] {
 
   override def distinctBy[B](f: A -> B): C = {
     if (lengthCompare(1) <= 0) coll

library/src/scala/collection/immutable/WrappedString.scala

@@ -37,8 +37,7 @@ import scala.collection.mutable.{Builder, StringBuilder}
 @SerialVersionUID(3L)
 final class WrappedString(private val self: String) extends AbstractSeq[Char] with IndexedSeq[Char]
   with IndexedSeqOps[Char, IndexedSeq, WrappedString]
-  with Serializable
-  with caps.Pure {
+  with Serializable {
 
   def apply(i: Int): Char = self.charAt(i)
 

library/src/scala/collection/mutable/IndexedSeq.scala

@@ -29,8 +29,7 @@ object IndexedSeq extends SeqFactory.Delegate[IndexedSeq](ArrayBuffer)
 
 transparent trait IndexedSeqOps[A, +CC[_] <: caps.Pure, +C <: AnyRef]
   extends scala.collection.IndexedSeqOps[A, CC, C]
-    with SeqOps[A, CC, C]
-    with caps.Pure {
+    with SeqOps[A, CC, C] {
 
   /** Modifies this $coll by applying a function to all elements of this $coll.
     *