Disable f64 minimum/maximum tests for arm 32

This disables the f64 minimum/maximum tests for the
arm-unknown-linux-gnueabihf job. The next release will be supporting
cross-compiled doctests, and these tests fail on that platform.

It looks like this was just fixed via
llvm/llvm-project#142170, but I assume that will
not trickle down to our copy of llvm in the next couple of weeks.
Assuming that does get fixed when llvm is updated, then these can be
removed.

cc rust-lang#141087

Author: ehuss

library/core/src/num/f64.rs

@@ -943,7 +943,7 @@ impl f64 {
     /// This returns NaN when *either* argument is NaN, as opposed to
     /// [`f64::max`] which only returns NaN when *both* arguments are NaN.
     ///
-    /// ```
+    /// ```ignore-arm-unknown-linux-gnueabihf (see https://github.com/rust-lang/rust/issues/141087)
     /// #![feature(float_minimum_maximum)]
     /// let x = 1.0_f64;
     /// let y = 2.0_f64;
@@ -970,7 +970,7 @@ impl f64 {
     /// This returns NaN when *either* argument is NaN, as opposed to
     /// [`f64::min`] which only returns NaN when *both* arguments are NaN.
     ///
-    /// ```
+    /// ```ignore-arm-unknown-linux-gnueabihf (see https://github.com/rust-lang/rust/issues/141087)
     /// #![feature(float_minimum_maximum)]
     /// let x = 1.0_f64;
     /// let y = 2.0_f64;