chore(deps): bump com.slack.api:bolt-jakarta-socket-mode in /backend

Bumps [com.slack.api:bolt-jakarta-socket-mode](https://github.com/slackapi/java-slack-sdk) from 1.48.0 to 1.50.0.
- [Release notes](https://github.com/slackapi/java-slack-sdk/releases)
- [Commits](slackapi/java-slack-sdk@v1.48.0...v1.50.0)

---
updated-dependencies:
- dependency-name: com.slack.api:bolt-jakarta-socket-mode
  dependency-version: 1.49.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

backend/pom.xml

@@ -159,7 +159,7 @@
         <dependency>
             <groupId>com.slack.api</groupId>
             <artifactId>bolt-jakarta-socket-mode</artifactId>
-            <version>1.48.0</version>
+            <version>1.50.0</version>
         </dependency>
         <dependency>
             <groupId>jakarta.websocket</groupId>