[CI/Build] Add shell script linting using shellcheck (#7925)

Signed-off-by: Russell Bryant <rbryant@redhat.com>

benchmarks/launch_tgi_server.sh

@@ -4,13 +4,13 @@ PORT=8000
 MODEL=$1
 TOKENS=$2
 
-docker run -e HF_TOKEN=$HF_TOKEN --gpus all --shm-size 1g -p $PORT:80 \
-           -v $PWD/data:/data \
+docker run -e "HF_TOKEN=$HF_TOKEN" --gpus all --shm-size 1g -p $PORT:80 \
+           -v "$PWD/data:/data" \
            ghcr.io/huggingface/text-generation-inference:2.2.0 \
-           --model-id $MODEL \
+           --model-id "$MODEL" \
            --sharded false  \
            --max-input-length 1024 \
            --max-total-tokens 2048 \
            --max-best-of 5 \
            --max-concurrent-requests 5000 \
-           --max-batch-total-tokens $TOKENS
+           --max-batch-total-tokens "$TOKENS"