Update frigate-install.sh

The silent() function (used when \=silent in non-verbose mode) calls
exit on any non-zero return code. This prevents the if/else fallback
pattern from ever reaching the else branch, causing the entire install
to abort instead of gracefully falling back to CPU model.

The upstream TF/OpenVino symbol incompatibility (_ZN6tflite15metrics_wrapper...)
is not something we can fix, but the graceful fallback should work correctly.

Replaced \ with direct output suppression (&>/dev/null) so the if
condition properly evaluates the return code.

Ref #12689

install/frigate-install.sh

@@ -208,7 +208,7 @@ msg_info "Building OpenVino Model"
 cd /models
 wget -q http://download.tensorflow.org/models/object_detection/ssdlite_mobilenet_v2_coco_2018_05_09.tar.gz
 $STD tar -zxf ssdlite_mobilenet_v2_coco_2018_05_09.tar.gz --no-same-owner
-if $STD python3 /opt/frigate/docker/main/build_ov_model.py; then
+if python3 /opt/frigate/docker/main/build_ov_model.py &>/dev/null; then
   cp /models/ssdlite_mobilenet_v2.xml /openvino-model/
   cp /models/ssdlite_mobilenet_v2.bin /openvino-model/
   wget -q https://github.com/openvinotoolkit/open_model_zoo/raw/master/data/dataset_classes/coco_91cl_bkgr.txt -O /openvino-model/coco_91cl_bkgr.txt