fix: use the right param type (#26469)

Jenkins, as expected, is honouring the param type used in the caller, but
not honouring the type in the triggered pipeline. This issue has historical
rationale, as the parameters are created dynamically

.ci/packaging.groovy

@@ -431,7 +431,7 @@ def triggerE2ETests(String suite) {
     booleanParam(name: 'forceSkipGitChecks', value: true),
     booleanParam(name: 'forceSkipPresubmit', value: true),
     booleanParam(name: 'notifyOnGreenBuilds', value: !isPR()),
-    booleanParam(name: 'BEAT_VERSION', value: beatVersion),
+    string(name: 'BEAT_VERSION', value: beatVersion),
     booleanParam(name: 'BEATS_USE_CI_SNAPSHOTS', value: true),
     string(name: 'runTestsSuites', value: suite),
     string(name: 'GITHUB_CHECK_NAME', value: env.GITHUB_CHECK_E2E_TESTS_NAME),