[CI] Bump `num_speculative_tokens` to 3 in nightly DeepSeek tests (#35882)

Signed-off-by: Matthew Bonanni <mbonanni@redhat.com>

tests/evals/gsm8k/configs/DeepSeek-R1-DP.yaml

@@ -8,4 +8,4 @@ server_args: >-
   --max-model-len 4096
   --data-parallel-size 8
   --enable-expert-parallel
-  --speculative-config '{"method":"mtp","num_speculative_tokens":1}'
+  --speculative-config '{"method":"mtp","num_speculative_tokens":3}'

tests/evals/gsm8k/configs/DeepSeek-R1-TP.yaml

@@ -8,4 +8,4 @@ server_args: >-
   --max-model-len 4096
   --tensor-parallel-size 8
   --enable-expert-parallel
-  --speculative-config '{"method":"mtp","num_speculative_tokens":1}'
+  --speculative-config '{"method":"mtp","num_speculative_tokens":3}'

tests/evals/gsm8k/configs/DeepSeek-V3.2-DP.yaml

@@ -8,4 +8,4 @@ server_args: >-
   --max-model-len 4096
   --data-parallel-size 8
   --enable-expert-parallel
-  --speculative-config '{"method":"mtp","num_speculative_tokens":1}'
+  --speculative-config '{"method":"mtp","num_speculative_tokens":3}'

tests/evals/gsm8k/configs/DeepSeek-V3.2-TP.yaml

@@ -8,4 +8,4 @@ server_args: >-
   --max-model-len 4096
   --tensor-parallel-size 8
   --enable-expert-parallel
-  --speculative-config '{"method":"mtp","num_speculative_tokens":1}'
+  --speculative-config '{"method":"mtp","num_speculative_tokens":3}'