Remove unused DocIdSet#all method

DocIdSet#all is no longer relevant since Query and Filter were merged.
We can remove it.

lucene/core/src/java/org/apache/lucene/search/DocIdSet.java

@@ -48,26 +48,6 @@ public long ramBytesUsed() {
         }
       };
 
-  /** A {@code DocIdSet} that matches all doc ids up to a specified doc (exclusive). */
-  public static DocIdSet all(int maxDoc) {
-    return new DocIdSet() {
-      @Override
-      public DocIdSetIterator iterator() throws IOException {
-        return DocIdSetIterator.all(maxDoc);
-      }
-
-      @Override
-      public Bits bits() throws IOException {
-        return new Bits.MatchAllBits(maxDoc);
-      }
-
-      @Override
-      public long ramBytesUsed() {
-        return Integer.BYTES;
-      }
-    };
-  }
-
   /**
    * Provides a {@link DocIdSetIterator} to access the set. This implementation can return <code>
    * null</code> if there are no docs that match.