[Deprecation][2/N] Replace --task with --runner and --convert (#21470)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>
Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
Co-authored-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

tests/models/multimodal/generation/test_qwen2_vl.py

@@ -267,7 +267,7 @@ def run_embedding_input_test(
 
     # max_model_len should be greater than image_feature_size
     with vllm_runner(model,
-                     task="generate",
+                     runner="generate",
                      max_model_len=4000,
                      max_num_seqs=3,
                      dtype=dtype,