chore(deps): bump modelcontextprotocol/conformance from 0.1.11 to 0.1.15

Bumps [modelcontextprotocol/conformance](https://github.com/modelcontextprotocol/conformance) from 0.1.11 to 0.1.15.
- [Release notes](https://github.com/modelcontextprotocol/conformance/releases)
- [Commits](modelcontextprotocol/conformance@v0.1.11...v0.1.15)

---
updated-dependencies:
- dependency-name: modelcontextprotocol/conformance
  dependency-version: 0.1.15
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

.github/workflows/conformance.yml

@@ -27,7 +27,7 @@ jobs:
           timeout 30 bash -c 'until curl -s http://localhost:8080/mcp > /dev/null 2>&1; do sleep 0.5; done'
 
       - name: Run conformance tests
-        uses: modelcontextprotocol/conformance@v0.1.11
+        uses: modelcontextprotocol/conformance@v0.1.15
         with:
           mode: server
           url: http://localhost:8080/mcp
@@ -54,7 +54,7 @@ jobs:
         run: mvn clean install -DskipTests
 
       - name: Run conformance test
-        uses: modelcontextprotocol/conformance@v0.1.11
+        uses: modelcontextprotocol/conformance@v0.1.15
         with:
           mode: client
           command: 'java -jar conformance-tests/client-jdk-http-client/target/client-jdk-http-client-*-SNAPSHOT.jar'