ci: fix smoke-zts PID lookup — php:*-zts has no pgrep

The smoke-zts step found the target PID with `pgrep -n -x php` inside the
container, but the official php:*-zts image ships no procps, so pgrep is
absent and the command aborted the `bash -e` step with exit 127 — before
pfp ever ran. The job never passed since it was added.

php runs as PID 1 in the container (docker-php-entrypoint execs the
command), so use PHP_PID=1 directly, mirroring the NTS smoke job's use of
the known PID. Verified locally end-to-end against php:8.3-zts: pfp
attaches to pid 1, detects 8.3.31, captures 199 samples with W::a/W::b.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: loks0n

.github/workflows/ci.yml

@@ -189,8 +189,9 @@ jobs:
           sleep 1
           docker exec php-zts php -i 2>/dev/null | grep -i 'thread safety' \
             | grep -qi enabled
-          PHP_PID=$(docker exec php-zts pgrep -n -x php)
-          test -n "$PHP_PID"
+          # php is the container's PID 1 — the docker-php-entrypoint execs
+          # the command — and the php:*-zts image ships no pgrep (no procps).
+          PHP_PID=1
           docker exec php-zts /pfp -p "$PHP_PID" -d 2 -H 99 -o /tmp/out.txt
           OUT=$(docker exec php-zts cat /tmp/out.txt)
           docker rm -f php-zts