teflon/tests: avoid loading build-tree tensorflow-lite stub at runtime

It can be quite confusing to see the tests failing to load models
without knowing why. To avoid making people waste time with strace, link
with the stubs at build time but look for the actual implementation at
run time.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/40269>

src/gallium/targets/teflon/meson.build

@@ -18,9 +18,10 @@ libteflon = shared_library(
 
 if with_tests
   tensorflow_lite = shared_library(
-    'tensorflow-lite',
+    'tensorflow-lite-stub',
     [ 'tflite-stub.c' ],
     include_directories : [ inc_include ],
+    link_args : [ '-Wl,-soname,libtensorflow-lite.so' ],
     install : false,
   )