docs: remove starchart.cc embed (#300)

starchart.cc is rate limited and rendering a broken image.

Refs: caarlos0/starcharts#260

Signed-off-by: Carlos Alexandro Becker <caarlos0@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: caarlos0

README.md

@@ -126,10 +126,6 @@ Or download one from the [releases tab](https://github.com/caarlos0/svu/releases
 
 </details>
 
-## stargazers over time
-
-[![Stargazers over time](https://starchart.cc/caarlos0/svu.svg?variant=adaptive)](https://starchart.cc/caarlos0/svu)
-
 [Semver]: https://semver.org
 
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