[correctness] Fix LSET modifying elements for out-of-range 64-bit indexes (#4823)

## Problem

  On 64-bit builds, `LSET` parses its index as `long`, but
  `listTypeReplaceAtIndex()` narrowed it to `int`. An out-of-range index
such as `4294967296` became `0`, causing `LSET` to return `OK` and
modify
  the first element instead of returning `ERR index out of range`.

This is a correctness issue affecting both listpack and quicklist lists.

  ## Fix

  Preserve the `long` index through `listTypeReplaceAtIndex()` so an
  out-of-range index returns an error without modifying the list. Add
regression tests for large positive and negative indexes in both
encodings.

  ## Tests

  - `./runtest --single unit/type/list --quiet`: 289 passed, 0 failed.
- Confirmed the command returns `ERR index out of range` and leaves the
    list unchanged after the fix.

  On 32-bit builds, these values are rejected when parsing the `long`
  index; the narrowing bug occurs on 64-bit builds.

---------

Signed-off-by: DaeMyung Kang <charsyam@gmail.com>
Backport-Source-PR: 4823

src/t_list.c

@@ -363,7 +363,7 @@ void listTypeReplace(listTypeEntry *entry, robj *value) {
  *
  * Returns 1 if replace happened.
  * Returns 0 if replace failed and no changes happened. */
-int listTypeReplaceAtIndex(robj *o, int index, robj *value) {
+int listTypeReplaceAtIndex(robj *o, long index, robj *value) {
     value = getDecodedObject(value);
     sds vstr = value->ptr;
     size_t vlen = sdslen(vstr);

tests/unit/type/list.tcl

@@ -1971,6 +1971,14 @@ foreach {type large} [array get largevalue] {
         test "LSET out of range index - $type" {
             assert_error ERR*range* {r lset mylist 10 foo}
         }
+
+        test "LSET does not truncate large indexes - $type" {
+            create_$type mylist "a $large"
+            foreach index {4294967295 4294967296 -4294967296 -4294967297} {
+                assert_error ERR*range* {r lset mylist $index changed} "LSET index $index"
+                assert_equal "a $large" [r lrange mylist 0 -1] "LSET index $index"
+            }
+        }
     }
 
     test {LSET against non existing key} {