fix: replace doc_auto_cg with doc_cfg

Author: joshstoik1

jpegxl-rs/src/lib.rs

@@ -15,7 +15,7 @@ You should have received a copy of the GNU General Public License
 along with jpegxl-rs.  If not, see <https://www.gnu.org/licenses/>.
 */
 
-#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 #![cfg_attr(coverage_nightly, feature(coverage_attribute))]
 #![doc = include_str!("../README.md")]