tests: qemucaps: Temporarily remove 'query-qmp-schema' from test data

Remove the command from the supported commands list temporarily so that
QMP introspection code can be added without breaking tests and having to
tweak the test data in the same commit.

This will be later reverted and test data will be added. The aarch64
code is special as it calls additional commands and thus the test data
can't be added upfront.

tests/qemucapabilitiesdata/caps_2.6.0-gicv2.aarch64.replies

@@ -220,9 +220,6 @@
     {
       "name": "query-chardev"
     },
-    {
-      "name": "query-qmp-schema"
-    },
     {
       "name": "query-events"
     },

tests/qemucapabilitiesdata/caps_2.6.0-gicv3.aarch64.replies

@@ -220,9 +220,6 @@
     {
       "name": "query-chardev"
     },
-    {
-      "name": "query-qmp-schema"
-    },
     {
       "name": "query-events"
     },