fix(tool): remove redundant dependency for streamx generation code

[DMwangnima]

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fix

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fix(工具): 移除 streamx 生成代码中的冗余依赖

(Optional) More detailed description for this PR(en: English/zh: Chinese).

en:
When generating streamx code with -thrift no_fmt, github.com/cloudwego/kitex/pkg/streamx is referenced twice:

"github.com/cloudwego/kitex/pkg/streamx"
"github.com/cloudwego/kitex/client/streamxclient/streamxcallopt"
"github.com/cloudwego/kitex/pkg/streamx"

Need to remove github.com/cloudwego/kitex/pkg/stream from the template since it is duplicated in the setImports.
zh(optional):
当使用-thrift no_fmt生成 streamx 代码时，github.com/cloudwego/kitex/pkg/streamx会被重复引用：

"github.com/cloudwego/kitex/pkg/streamx"
"github.com/cloudwego/kitex/client/streamxclient/streamxcallopt"
"github.com/cloudwego/kitex/pkg/streamx"

需要将模版中的github.com/cloudwego/kitex/pkg/stream移除，和 setImports 中添加的依赖重复了。

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