Resolve linking issue flagged in 7.0.0-dev7 (#7595)

Author: achamayou

cmake/ccf_app.cmake

@@ -37,6 +37,13 @@ function(add_ccf_app name)
     target_link_options(${name} PRIVATE LINKER:--no-undefined)
   endif()
 
+  # Tracked in https://github.com/microsoft/CCF/issues/7596. Workaround for a
+  # circular dependency between ccf.a and ccfcrypto.a
+  target_link_options(
+    ${name} PRIVATE
+    LINKER:--undefined=_ZN3ccf9threading21get_current_thread_idEv
+  )
+
   set_property(TARGET ${name} PROPERTY POSITION_INDEPENDENT_CODE ON)
 
   add_san(${name})