MINOR: Add release note for Java 17 requirement (#18302)

Also remove confusing comment related to connect & Java 17 from build.gradle.
I also updated KIP-1013 to note the implications of KIP-1032.

Reviewers: Chia-Ping Tsai <[email protected]>

Author: ijuma

build.gradle

@@ -49,7 +49,6 @@ ext {
   gradleVersion = versions.gradle
   minClientJavaVersion = 11
   minNonClientJavaVersion = 17
-  // The connect:api module also belongs to the clients module, but it has already been bumped to JDK 17 as part of KIP-1032.
   modulesNeedingJava11 = [":clients", ":generator", ":streams", ":streams:test-utils", ":streams-scala", ":test-common:test-common-runtime"]
 
   buildVersionFileName = "kafka-version.properties"

docs/upgrade.html

@@ -224,17 +224,19 @@ <h5><a id="upgrade_400_notable" href="#upgrade_400_notable">Notable changes in 4
         </li>
         <li>Other changes:
             <ul>
+                <li>
+                    The minimum Java version required by clients and streams applications has been increased from Java 8 to Java 11
+                    while brokers, connect and tools now require Java 17.
+                    See <a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=181308223">KIP-750</a> and
+                    <a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=284789510">KIP-1013</a> for more details.
+                </li>
                 <li>
                     Java 23 support has been added in Apache Kafka 4.0
                 </li>
                 <li>
                     Scala 2.12 support has been removed in Apache Kafka 4.0
                     See <a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=181308218">KIP-751</a> for more details
                 </li>
-                <li>
-                    Java 8 support has been removed in Apache Kafka 4.0
-                    See <a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=181308223">KIP-750</a> for more details
-                </li>
                 <li>
                     KafkaLog4jAppender has been removed, users should migrate to the log4j2 appender
                     See <a href="https://logging.apache.org/log4j/2.x/manual/appenders.html#KafkaAppender">KafkaAppender</a> for more details