tests: thrift: build_only until c++11 threads are in sdk

There was a make-shift mutex implementation added to thrift
while waiting for C++11 thread support in the SDK. This was
fairly racey and would cause issues in CI regularly.

Make the tests build-only for now until C++11 thread, mutex,
etc support is stabilized.

Signed-off-by: Chris Friedt <chrisfriedt@gmail.com>

tests/modules/thrift/ThriftTest/testcase.yaml

@@ -1,4 +1,5 @@
 common:
+  build_only: true
   tags:
     - thrift
     - cpp