Remove deprecated method from 2.x (#6769)

Author: JakeWharton

src/main/java/io/reactivex/rxjava3/internal/functions/ObjectHelper.java

@@ -128,17 +128,4 @@ public boolean test(Object o1, Object o2) {
             return ObjectHelper.equals(o1, o2);
         }
     }
-
-    /**
-     * Trap null-check attempts on primitives.
-     * @param value the value to check
-     * @param message the message to print
-     * @return the value
-     * @deprecated this method should not be used as there is no need
-     * to check primitives for nullness.
-     */
-    @Deprecated
-    public static long requireNonNull(long value, String message) {
-        throw new InternalError("Null check on a primitive: " + message);
-    }
 }

src/test/java/io/reactivex/rxjava3/internal/functions/ObjectHelperTest.java

@@ -67,10 +67,4 @@ public void compareLong() {
         assertEquals(0, ObjectHelper.compare(0L, 0L));
         assertEquals(1, ObjectHelper.compare(2L, 0L));
     }
-
-    @SuppressWarnings("deprecation")
-    @Test(expected = InternalError.class)
-    public void requireNonNullPrimitive() {
-        ObjectHelper.requireNonNull(0, "value");
-    }
 }