race condition when calling Theme.Tips concurrently

[unkmonster]

System (please complete the following information):

• OS: window [e.g. linux, macOS]
• GO Version: 1.13 [e.g. 1.13]
• Pkg Version: 1.1.1 [e.g. 1.1.1]

ENV info on the terminal (by command env | grep -i TERM)

// paste env info.
Windows 11 Terminal

Describe the bug

Multiple goroutines calling Theme.Tips concurrently may cause mixed output

Since both t.Print and Printf perform I/O operations, concurrent writes to the output may lead to interleaved output.

To Reproduce

// go code
go func1() {
   color.Warn.Tips("some text 1")
}()

go func2() {
   color.Error.Tips("some text 2")
}()

Expected behavior

concurrent calls can output correctly

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Additional context

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