Fix `ZookeeperConfigWatcherRegister.readConfig()` could cause `NPE` when `data.getData()` is null (#7611)

Fix dynamic configuration watch implementation current value not null when the config is deleted. (#7606)

* Fix dynamic configuration watch implementation current value not null when the config is deleted.

* add changes.md

* fix LoggingConfigWatcher watch.vale, and when value = null ,config not reset.

* fix

* fix style

* Update oap-server/analyzer/agent-analyzer/src/main/java/org/apache/skywalking/oap/server/analyzer/provider/trace/UninstrumentedGatewaysConfig.java
Co-authored-by: Nkezhenxu94 <kezhenxu94@apache.org>

* use Strings.nullToEmpty
Co-authored-by: 吴晟 Wu Sheng <wu.sheng@foxmail.com>
Co-authored-by: Nkezhenxu94 <kezhenxu94@apache.org>

* Remove agent codes and clean up

* Reorganize dynamic configuration doc

* add configmap and polish doc

* polish changes.md

* Support k8s configmap grouped dynamic configurations

* Support single config read from multiple configmaps

* Support grouped dynamic configurations in DCS.
Support zookeeper grouped dynamic configurations.

* change to @Slf4j
Co-authored-by: 吴晟 Wu Sheng <wu.sheng@foxmail.com>

Also use `quiet` mode for all maven commands in GHA, we can still see errors when there is failure
Co-authored-by: 吴晟 Wu Sheng <wu.sheng@foxmail.com>

* Refine dynamic-config.md

* Refine dynamical-logging.md

* Refine endpoint-grouping-rules.md

`uses` is recently allowed in `composite` actions, we can simplify our workflows control files further.