ci(vagrant): add OpenBSD 6.9 [skip ci]

* Automated using https://github.com/myii/ssf-formula/pull/327

.github/workflows/kitchen.vagrant.yml

@@ -20,6 +20,7 @@ jobs:
           # - default-freebsd-130-3002-6-py3
           # - default-freebsd-122-3002-6-py3
           # - default-freebsd-114-3002-6-py3
+          - default-openbsd-69-3002-6-py3
           - default-openbsd-68-3001-1-py3
     steps:
       - name: 'Check out code'

kitchen.vagrant.yml

@@ -38,6 +38,12 @@ platforms:
   - name: freebsd-114-3002-6-py3
     driver:
       box: myii/freebsd-11.4-3002.6-py3
+  - name: openbsd-69-3002-6-py3
+    driver:
+      box: myii/openbsd-6.9-3002.6-py3
+      ssh:
+        shell: /bin/ksh
+      synced_folders: []
   - name: openbsd-68-3001-1-py3
     driver:
       box: myii/openbsd-6.8-3001.1-py3