Increment Go build version to 1.21.3 (#29119)

* Increment Go build version to 1.21.3

* Fix security fixes markdown links

CHANGES.md

@@ -88,7 +88,8 @@ as a workaround, a copy of "old" `CountingSource` class should be placed into a
 * `watch_file_pattern` arg of the [RunInference](https://github.com/apache/beam/blob/104c10b3ee536a9a3ea52b4dbf62d86b669da5d9/sdks/python/apache_beam/ml/inference/base.py#L997) arg had no effect prior to 2.52.0. To use the behavior of arg `watch_file_pattern` prior to 2.52.0, follow the documentation at https://beam.apache.org/documentation/ml/side-input-updates/ and use `WatchFilePattern` PTransform as a SideInput. ([#28948](https://github.com/apache/beam/pulls/28948))
 
 ## Security Fixes
-* Fixed (CVE-YYYY-NNNN)[https://www.cve.org/CVERecord?id=CVE-YYYY-NNNN] (Java/Python/Go) ([#X](https://github.com/apache/beam/issues/X)).
+* Fixed [CVE-YYYY-NNNN](https://www.cve.org/CVERecord?id=CVE-YYYY-NNNN) (Java/Python/Go) ([#X](https://github.com/apache/beam/issues/X)).
+* Fixed [CVE-2023-39325](https://www.cve.org/CVERecord?id=CVE-2023-39325) (Java/Python/Go) ([#29118](https://github.com/apache/beam/issues/29118)).
 
 ## Known Issues
 

buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy

@@ -2197,7 +2197,7 @@ class BeamModulePlugin implements Plugin<Project> {
       def goRootDir = "${project.rootDir}/sdks/go"
 
       // This sets the whole project Go version.
-      project.ext.goVersion = "go1.21.2"
+      project.ext.goVersion = "go1.21.3"
 
       // Minor TODO: Figure out if we can pull out the GOCMD env variable after goPrepare script
       // completion, and avoid this GOBIN substitution.