Change DeepSeek max token count to 128k (#36864)

https://api-docs.deepseek.com/zh-cn/news/news250821

Now the official API supports 128k token content

and have modify the name to v3.1/v3.1 thinking

Release Notes:

- N/A

---------

Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>

crates/deepseek/src/deepseek.rs

@@ -96,7 +96,7 @@ impl Model {
 
     pub fn max_token_count(&self) -> u64 {
         match self {
-            Self::Chat | Self::Reasoner => 64_000,
+            Self::Chat | Self::Reasoner => 128_000,
             Self::Custom { max_tokens, .. } => *max_tokens,
         }
     }
@@ -104,7 +104,7 @@ impl Model {
     pub fn max_output_tokens(&self) -> Option<u64> {
         match self {
             Self::Chat => Some(8_192),
-            Self::Reasoner => Some(8_192),
+            Self::Reasoner => Some(64_000),
             Self::Custom {
                 max_output_tokens, ..
             } => *max_output_tokens,