PG18 - Strip decimal fractions from actual rows counts in normalize.sed (#8041)

Fixes #8040 

```
- Custom Scan (Citus Adaptive) (actual rows=0 loops=1)
+ Custom Scan (Citus Adaptive) (actual rows=0.00 loops=1)
```


Add a normalization rule to the pg_regress `normalize.sed` script that
strips any trailing decimal fraction from actual rows= counts (e.g.
turning `actual rows=0.00` into `actual rows=0`). This silences noise
diffs introduced by the new PostgreSQL 18 beta’s planner output.

commit b06bde5771

src/test/regress/bin/normalize.sed

@@ -325,3 +325,6 @@ s/\| CHECK ([a-zA-Z])(.*)/| CHECK \(\1\2\)/g
 # supported Postgres version.
 
 /DEBUG:  drop auto-cascades to type [a-zA-Z_]*.pg_temp_[0-9]*/d
+
+# pg18 change: strip trailing “.00” (or “.0…”) from actual rows counts
+s/(actual rows=[0-9]+)\.[0-9]+/\1/g