Remove deprecated modules (#1985)

* Delete JMS appender (#1966)
* Delete SMTP appender (#1966)
* Delete Jakarta SMTP appender (#1966)
* Delete `*-web`, `-jpa`, `-taglib`, and other leftovers (#1966)
* Add changelog entries (#1966)
* Remove `log4j-cassandra`
* Remove `log4j-couchdb`
* Remove `log4j-kafka`
* Remove `log4j-mongodb3`
* Remove `log4j-spring-boot`
* Remove `GelfLayout`
* Remove `log4j-layout-jackson-yaml`
* Remove `log4j-jeromq`
* Remove `log4j-layout-jackson-json`
* Merge `log4j-spring-cloud-config` into `log4j-spring-cloud-config-client`

Author: vy

Diff for: .github/dependabot.yml

@@ -51,9 +51,6 @@ updates:
     # JUnit Pioneer 2.x requires Java 11
     - dependency-name: "org.junit-pioneer:*"
       update-types: ["version-update:semver-major"]
-    # Apache Cassandra: keep version 3.x
-    - dependency-name: "org.apache.cassandra:*"
-      versions: ["[4.0.0,)"]
     # Kubernetes: keep version 5.x
     - dependency-name: "io.fabric8:*"
       versions: ["[6.0.0,)"]