Remove initialisation of unions

As of gcc-15, unions are no longer zero initialised when "{0}" is used.
To revert to the old behaviour, either assumes building for C23 or
adding a compiler option that may or may not work with other compilers.

Remove current "initialization" to make it clear that full initialization
is not occuring. All relevant fields are currently initialized before
use.

Signed-off-by: Allan McRae <allan@archlinux.org>

lib/libalpm/dload.c

@@ -1322,7 +1322,7 @@ int SYMEXPORT alpm_fetch_pkgurl(alpm_handle_t *handle, const alpm_list_t *urls,
 	char *temporary_cachedir = NULL;
 	alpm_list_t *payloads = NULL;
 	const alpm_list_t *i;
-	alpm_event_t event = {0};
+	alpm_event_t event;
 
 	CHECK_HANDLE(handle, return -1);
 	ASSERT(*fetched == NULL, RET_ERR(handle, ALPM_ERR_WRONG_ARGS, -1));

lib/libalpm/sync.c

@@ -776,7 +776,7 @@ static int download_files(alpm_handle_t *handle)
 	char * temporary_cachedir = NULL;
 	alpm_list_t *i, *files = NULL;
 	int ret = 0;
-	alpm_event_t event = {0};
+	alpm_event_t event;
 	alpm_list_t *payloads = NULL;
 
 	cachedir = _alpm_filecache_setup(handle);