Bump org.apache.maven.plugins:maven-enforcer-plugin in /spec

Bumps [org.apache.maven.plugins:maven-enforcer-plugin](https://github.com/apache/maven-enforcer) from 3.6.2 to 3.6.3.
- [Release notes](https://github.com/apache/maven-enforcer/releases)
- [Commits](https://github.com/apache/maven-enforcer/compare/enforcer-3.6.2...enforcer-3.6.3)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-enforcer-plugin
  dependency-version: 3.6.3
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

spec/pom.xml

diff --git a/spec/pom.xml b/spec/pom.xml
index d21434b..6dd03e6 100644
--- a/spec/pom.xml
+++ b/spec/pom.xml
@@ -40,7 +40,7 @@
         <!-- status: DRAFT, BETA, etc., or blank for final -->
         <status>DRAFT</status>
         <maven.build.timestamp.format>MMMM dd, yyyy</maven.build.timestamp.format>
-        <maven.enforcer.plugin.version>3.6.2</maven.enforcer.plugin.version>
+        <maven.enforcer.plugin.version>3.6.3</maven.enforcer.plugin.version>
         <revisiondate>${maven.build.timestamp}</revisiondate>
     </properties>