Add 3.6 PR to pr-ci-testing

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
Change-Id: I9df5262a1ad0e03f2978b3725c55baee4f2fd770
diff --git a/mbed-tls-restricted-pr-ci-testing.yaml b/mbed-tls-restricted-pr-ci-testing.yaml
index 02d0cb0..ddeb871 100644
--- a/mbed-tls-restricted-pr-ci-testing.yaml
+++ b/mbed-tls-restricted-pr-ci-testing.yaml
@@ -44,7 +44,7 @@
         repo: mbedtls-restricted
         branch-discovery: no-pr
         discover-pr-origin: both
-        head-filter-regex: 'PR-(758|759|806|850|906|916|919|1225|1227)-.*'
+        head-filter-regex: 'PR-(758|759|806|850|906|916|919|1225|1227|1233)-.*'
         status-checks:
           skip: true
           skip-branch-source-notifications: true