chore(deps-dev): bump org.keycloak:keycloak-core from 26.2.5 to 26.3.1

Bumps [org.keycloak:keycloak-core](https://github.com/keycloak/keycloak) from 26.2.5 to 26.3.1.
- [Release notes](https://github.com/keycloak/keycloak/releases)
- [Commits](keycloak/keycloak@26.2.5...26.3.1)

---
updated-dependencies:
- dependency-name: org.keycloak:keycloak-core
  dependency-version: 26.3.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -116,7 +116,7 @@
     <bouncycastle.version>1.81</bouncycastle.version>
     <bc-fips.version>2.1.0</bc-fips.version>
     <bcpkix-fips.version>2.1.9</bcpkix-fips.version>
-    <keycloak.version>26.2.5</keycloak.version><!-- Used by CRD Generator integration tests for verifications -->
+    <keycloak.version>26.3.1</keycloak.version><!-- Used by CRD Generator integration tests for verifications -->
     <mockito.version>5.18.0</mockito.version>
     <mockito-inline.version>5.2.0</mockito-inline.version>
     <spock.version>2.4-M6-groovy-4.0</spock.version>