Auto merge of #143294 - ChrisDenton:rename-mingw, r=Kobzol

Rename `mingw-*` CI jobs to `pr-*`

The name `mingw` confuses people because these CI jobs now do much more than just cross-compile to mingw.

This is basically a find/replace. I chose the name `pr-` because it's job is to do general PR checks,

Author: bors

src/tests/ci.md

@@ -66,8 +66,8 @@ kinds of builds (sets of jobs).
 ### Pull Request builds
 
 After each push to a pull request, a set of `pr` jobs are executed. Currently,
-these execute the `x86_64-gnu-llvm-X`, `x86_64-gnu-tools`, `mingw-check-1`, `mingw-check-2`
-and `mingw-check-tidy` jobs, all running on Linux. These execute a relatively short
+these execute the `x86_64-gnu-llvm-X`, `x86_64-gnu-tools`, `pr-check-1`, `pr-check-2`
+and `tidy` jobs, all running on Linux. These execute a relatively short
 (~40 minutes) and lightweight test suite that should catch common issues. More
 specifically, they run a set of lints, they try to perform a cross-compile check
 build to Windows mingw (without producing any artifacts) and they test the