[v1] Add Whisper model support (encoder-decoder) (#21088)

Signed-off-by: Russell Bryant <rbryant@redhat.com>
Co-authored-by: NickLucche <nlucches@redhat.com>

tests/models/test_initialization.py

@@ -68,6 +68,12 @@ def can_initialize(model_arch: str, monkeypatch: pytest.MonkeyPatch,
             # has cc==8.9 which hasn't supported FA3 yet. Remove this hack when
             # L4 supports FA3.
             m.setenv("VLLM_ATTENTION_BACKEND", "TRITON_ATTN_VLLM_V1")
+        if model_arch == "Florence2ForConditionalGeneration":
+            # An encoder-decoder model that's V0-only. Just skip it
+            # since V0 is about to be removed.
+            pytest.skip("Skipping Florence2ForConditionalGeneration")
+        if model_arch == "WhisperForConditionalGeneration":
+            m.setenv("VLLM_WORKER_MULTIPROC_METHOD", "spawn")
         LLM(
             model_info.default,
             tokenizer=model_info.tokenizer,