chore: use mise project root in native task

Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>

Author: zeitlinger

.mise/envs/native/mise.toml

@@ -4,5 +4,8 @@ java = "oracle-graalvm-25.0.1"
 [tasks.native-test]
 depends = "build"
 # Native Test uses Surefire, so explicitly select the Failsafe-named test class.
-run = "../../mvnw test -PnativeTest -Dtest=ApplicationIT"
-dir = "../../../integration-tests/it-spring-boot-smoke-test"
+run = '''
+repo_root="$MISE_PROJECT_ROOT/../../.."
+cd "$repo_root/integration-tests/it-spring-boot-smoke-test"
+"$repo_root/mvnw" test -PnativeTest -Dtest=ApplicationIT
+'''