Upgrade to Httpcore 4.4.12

Closes spring-projectsgh-18144

Author: snicoll

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

@@ -78,7 +78,7 @@
 		<htmlunit.version>2.33</htmlunit.version>
 		<httpasyncclient.version>4.1.4</httpasyncclient.version>
 		<httpclient.version>4.5.9</httpclient.version>
-		<httpcore.version>4.4.11</httpcore.version>
+		<httpcore.version>4.4.12</httpcore.version>
 		<infinispan.version>9.4.16.Final</infinispan.version>
 		<influxdb-java.version>2.14</influxdb-java.version>
 		<!-- deprecated in favor of "jackson-bom.version" -->