Revert "Upgrade to Jackson 2.9.9"

This reverts commit 66fba93.

See gh-16910

Author: wilkinsona

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -80,7 +80,7 @@
 		<httpcore.version>4.4.11</httpcore.version>
 		<infinispan.version>9.4.13.Final</infinispan.version>
 		<influxdb-java.version>2.14</influxdb-java.version>
-		<jackson.version>2.9.9</jackson.version>
+		<jackson.version>2.9.8</jackson.version>
 		<janino.version>3.0.12</janino.version>
 		<javax-activation.version>1.2.0</javax-activation.version>
 		<javax-annotation.version>1.3.2</javax-annotation.version>