[CALCITE-7169] Update protobuf from 3.25.5 to 3.25.8 in Avatica

Author: stoty

gradle.properties

@@ -76,7 +76,7 @@ junit.version=4.13.2
 kerby.version=2.1.0
 log4j2.version=2.17.1
 mockito.version=4.11.0
-protobuf.version=3.25.5
+protobuf.version=3.25.8
 scott-data-hsqldb.version=0.1
 servlet.version=4.0.1
 slf4j.version=1.7.25