bors squash left commit separate from PR/rollup in gh history

[klensy]

PR: rust-lang/rust#101806

And now check github history: https://github.com/rust-lang/rust/commits?author=bors for Sep 20, 2022, there separate non PR/rollup commit.

squash bors command should be disabled: it used rarely, and if used, it sometimes(often?) works not in way as it expected.

[klensy]

And that PR affected by #181 too.

[jyn514]

Duplicate of #181