Initialize SWOOLE_G(cli) to avoid reading uninitialized global under threaded SAPIs (#6107)

php_swoole_init_globals() initializes every module global except `cli`,
relying on the storage being zero-initialized. That holds for the CLI and
single-threaded embed SAPIs, but not for threaded/embedded SAPIs such as
FrankenPHP: each worker thread's module globals are allocated per thread and
are not guaranteed to be zeroed before the ctor runs, so `cli` reads an
indeterminate value.

There, sapi_module.name is the host SAPI's own name (e.g. "frankenphp"), so
the cli/phpdbg/embed/micro check never sets `cli`. When the leftover value is
non-zero, PHP_RINIT_FUNCTION(swoole) passes its `if (!SWOOLE_G(cli)) return`
guard and runs the request path, which calls swoole_set_task_tmpdir() and
dereferences the (uninitialized) per-thread buffer, segfaulting on the first
request.

Explicitly default `cli` to false so the guard is reliable regardless of SAPI.

Author: henderkes

ext-src/php_swoole.cc

@@ -384,6 +384,7 @@ static void php_swoole_init_globals(zend_swoole_globals *swoole_globals) {
     swoole_globals->blocking_threshold = 100000;
     swoole_globals->profile = false;
     swoole_globals->leak_detection = false;
+    swoole_globals->cli = false;
 
     if (strcmp("cli", sapi_module.name) == 0 || strcmp("phpdbg", sapi_module.name) == 0 ||
         strcmp("embed", sapi_module.name) == 0 || strcmp("micro", sapi_module.name) == 0) {