[chore](fe) Upgrade BDB JE to 18.3.18 (#69970)

### What problem does this PR solve?

Upgrade the FE BDB JE dependency to the latest Doris snapshot requested
for all active target branches.

### What is changed and how does it work?

- Update `je.version` in `fe/pom.xml` to `18.3.18-doris-SNAPSHOT`.

### Related PRs

- Canonical Apache Doris master PR:
https://github.com/apache/doris/pull/69970

### Check List

- [x] No local build or test was run, as requested for this
dependency-only version update.

Co-authored-by: gavinchou <gavinchou@apache.org>

fe/pom.xml

@@ -297,7 +297,7 @@ under the License.
         <javax.servlet-api.version>3.1.0</javax.servlet-api.version>
         <!-- Spring Framework 7 and Jetty EE11 require Jakarta Servlet 6.1. -->
         <jakarta.servlet-api.version>6.1.0</jakarta.servlet-api.version>
-        <je.version>18.3.14-doris-SNAPSHOT</je.version>
+        <je.version>18.3.18-doris-SNAPSHOT</je.version>
         <commons-io.version>2.18.0</commons-io.version>
         <commons-beanutils.version>1.11.0</commons-beanutils.version>
         <json-simple.version>1.1.1</json-simple.version>