Merge pull request apache#13819: [website] Clarify JIRA priority for …

…security issues (CVEs)

Beam release 2.27.0

[Gradle Release Plugin] - creating tag: 'v2.27.0-RC4'.

[Gradle Release Plugin] - creating tag: 'v2.27.0-RC3'.

[Gradle Release Plugin] - creating tag: 'v2.27.0-RC1'.

Apache Beam 2.26.0 Release

[Gradle Release Plugin] - creating tag: 'v2.26.0-RC1'.

[Gradle Release Plugin] - creating tag: 'v2.26.0-RC00'.

Apache Beam 2.25.0 release

[Gradle Release Plugin] - creating tag: 'v2.25.0-RC2'.