Fix use-after-free in hashtableTwoPhasePopDelete (#1626)

Use-after-free has been detect by address sanitizer, such as in this
test run:

https://github.com/valkey-io/valkey/actions/runs/12981530413/job/36200075972?pr=1620#step:5:1339

`hashtableShrinkIfNeeded` may free one of the hash tables and invalidate
the variables used by the `fillBucketHole(ht, b, pos_in_bucket,
table_index)` just after, causing use-after-free. Fill bucket hole first
and shrink afterwards is assumed to solve the issue. (Not reproduced
locally.)

Signed-off-by: Viktor Söderqvist <[email protected]>

src/hashtable.c

@@ -1518,7 +1518,6 @@ void hashtableTwoPhasePopDelete(hashtable *ht, hashtablePosition *pos) {
     assert(isPositionFilled(b, pos_in_bucket));
     b->presence &= ~(1 << pos_in_bucket);
     ht->used[table_index]--;
-    hashtableShrinkIfNeeded(ht);
     hashtableResumeRehashing(ht);
     if (b->chained && !hashtableIsRehashingPaused(ht)) {
         /* Rehashing paused also means bucket chain compaction paused. It is
@@ -1527,6 +1526,7 @@ void hashtableTwoPhasePopDelete(hashtable *ht, hashtablePosition *pos) {
          * we do the compaction in the scan and iterator code instead. */
         fillBucketHole(ht, b, pos_in_bucket, table_index);
     }
+    hashtableShrinkIfNeeded(ht);
 }
 
 /* Initializes the state for an incremental find operation.