Update tianon/buildkit:0.16 to sha256:ecca50f96da1555280b1413ffe9c86e0a0f96adc75497ffc33eb9cb0280d175f (#20008)

Co-authored-by: Docker Library Bot <[email protected]>

.external-pins/tianon/buildkit___0.16

@@ -1 +1 @@
-sha256:bf3219bf3838419d678be38d482b0a083cd8b41034306ac45b79a38e05e5a036
+sha256:ecca50f96da1555280b1413ffe9c86e0a0f96adc75497ffc33eb9cb0280d175f