general: Add a couple of missing EXPCLs

Although these aren't used outside of libpanda(express), they
are used by their neighboring component libraries, which means
they should be exported so that this works correctly when the
metalibs feature is disabled.

panda/src/express/config_express.h

@@ -48,7 +48,7 @@ extern ConfigVariableInt patchfile_increment_size;
 extern ConfigVariableInt patchfile_buffer_size;
 extern ConfigVariableInt patchfile_zone_size;
 
-extern ConfigVariableBool keep_temporary_files;
+extern EXPCL_PANDA_EXPRESS ConfigVariableBool keep_temporary_files;
 extern ConfigVariableBool multifile_always_binary;
 
 extern EXPCL_PANDA_EXPRESS ConfigVariableBool collect_tcp;

panda/src/pgraph/config_pgraph.h

@@ -48,7 +48,7 @@ extern ConfigVariableDouble garbage_collect_states_rate;
 extern ConfigVariableBool transform_cache;
 extern ConfigVariableBool state_cache;
 extern ConfigVariableBool uniquify_transforms;
-extern ConfigVariableBool uniquify_states;
+extern EXPCL_PANDA_PGRAPH ConfigVariableBool uniquify_states;
 extern ConfigVariableBool uniquify_attribs;
 extern ConfigVariableBool retransform_sprites;
 extern ConfigVariableBool depth_offset_decals;