CL 561935 - crypto CL that used purego tag and mentioned accepted-but-not-implemented proposal https://go.dev/issue/23172 to document purego tag; doesn't need a release note
CL 568340 - fixed a spurious race in time.Ticker.Reset (added via accepted proposal https://go.dev/issue/33184), doesn't seem to need a release note

become eligible for garbage collection immediately, even if their
`Stop` methods have not been called.
Earlier versions of Go did not collect unstopped `Timer`s until after
they had fired and never collected unstopped `Ticker`s.

<!-- go.dev/issue/37196 -->
Second, the timer channel associated with a `Timer` or `Ticker` is
now unbuffered, with capacity 0.
The main effect of this change is that Go now guarantees

// (although that comment isn't exactly right, as the value overwritten is not simulated correctly).
//    t1 = MINSD x, y   => incorrect if x==NaN or x==-0,y==+0
//    t2 = MINSD t1, x  => fixes x==NaN case
//   res = POR t1, t2   => fixes x==-0,y==+0 case
// Note that this trick depends on the special property that (NaN OR x) produces a NaN (although
// it might not produce the same NaN as the input).