Delete "no unsafe" claim from readme

"No unsafe" is misleading because there is unsafe code unconditionally
compiled into the crate.

It looks like this sentence in the readme was written in 408f42a and
"no unsafe" was true at that point, but then 48 hours later some unsafe
code was added in 8904b5e and has been there ever since. It seems like
an oversight that the readme was not updated.

README.md

@@ -33,7 +33,7 @@ A zero-allocation no_std-compatible zero-cost way to add color to your Rust term
     * [x] Truecolor support (modern, 48-bit color)
 * [x] Styling (underline, strikethrough, etc)
 
-owo-colors is also more-or-less a drop-in replacement for [colored](https://crates.io/crates/colored), allowing colored to work in a no_std environment. No allocations, unsafe, or dependencies required because embedded systems deserve to be pretty too uwu.
+owo-colors is also more-or-less a drop-in replacement for [colored](https://crates.io/crates/colored), allowing colored to work in a no_std environment. No allocations or dependencies required because embedded systems deserve to be pretty too uwu.
 
 To add to your Cargo.toml:
 ```toml