Bump quarkus.platform.version in /apps/unicorn-store-jakarta/quarkus

Bumps `quarkus.platform.version` from 3.19.1 to 3.21.1.

Updates `io.quarkus.platform:quarkus-bom` from 3.19.1 to 3.21.1
- [Commits](quarkusio/quarkus-platform@3.19.1...3.21.1)

Updates `io.quarkus.platform:quarkus-maven-plugin` from 3.19.1 to 3.21.1
- [Commits](quarkusio/quarkus-platform@3.19.1...3.21.1)

---
updated-dependencies:
- dependency-name: io.quarkus.platform:quarkus-bom
  dependency-version: 3.21.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.quarkus.platform:quarkus-maven-plugin
  dependency-version: 3.21.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

apps/unicorn-store-jakarta/quarkus/pom.xml

@@ -21,7 +21,7 @@
         <primefaces-quarkus.version>3.15.0</primefaces-quarkus.version>
         <quarkus.platform.artifact-id>quarkus-bom</quarkus.platform.artifact-id>
         <quarkus.platform.group-id>io.quarkus.platform</quarkus.platform.group-id>
-        <quarkus.platform.version>3.19.1</quarkus.platform.version>
+        <quarkus.platform.version>3.21.1</quarkus.platform.version>
         <jackson.version>2.18.3</jackson.version>
     </properties>