api: swagger: fix definition of TmpFsOptions (API v1.46)

Since it's a [][]string, there should only be two levels of array
in the OpenAPI spec. Also, the outermost level array shouldn't have
properties: (it should have items: instead).

Co-authored-by: Mark Yen <mark.yen@suse.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

docs/api/v1.46.yaml

@@ -449,15 +449,12 @@ definitions:
               should be provided as as 2-length arrays, where the first item is
               the key and the second the value.
             type: "array"
-            properties:
+            items:
+              type: "array"
+              minItems: 1
+              maxItems: 2
               items:
-                type: "array"
-                items:
-                  type: "array"
-                  minItems: 1
-                  maxItems: 2
-                  items:
-                    type: "string"
+                type: "string"
             example:
               [["noexec"]]