tests: reduce stress on CPU to 2 models (#12161)

* tests: reduce stress on CPU to 2 models

This should avoid flakes due to systems getting overloaded with 3 (or more) models running concurrently

* tests: allow slow systems to pass on timeout

If a slow system is still streaming a response, and the response
will pass validation, don't fail just because the system is slow.

* test: unload embedding models more quickly

integration/embed_test.go

@@ -38,8 +38,9 @@ func TestAllMiniLMEmbeddings(t *testing.T) {
 	defer cleanup()
 
 	req := api.EmbeddingRequest{
-		Model:  "all-minilm",
-		Prompt: "why is the sky blue?",
+		Model:     "all-minilm",
+		Prompt:    "why is the sky blue?",
+		KeepAlive: &api.Duration{Duration: 10 * time.Second},
 	}
 
 	res, err := embeddingTestHelper(ctx, client, t, req)