Update the scheduler message when preponing

[nightkr]

Motivation

In practice this should update the reconciliation reason, fixing #1114. Obsoletes #1241.

Solution

hashbrown::HashMap lets us update the key, as long as the new value is still considered equivalent to the old one (in terms of both Eq and Hash). We can't update the version of the value stored in the DelayQueue, so instead we have to ensure that we resolve it via the HashMap.

[codecov]

Codecov Report

Merging #1260 (c60f8cc) into main (db585dd) will increase coverage by 0.68%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1260      +/-   ##
==========================================
+ Coverage   72.60%   73.28%   +0.68%     
==========================================
  Files          72       75       +3     
  Lines        5899     6057     +158     
==========================================
+ Hits         4283     4439     +156     
- Misses       1616     1618       +2     

Impacted Files	Coverage Δ
kube-runtime/src/scheduler.rs	97.38% <100.00%> (+0.43%)	⬆️

... and 19 files with indirect coverage changes

[clux]

nice easy solution hashbrown is already in dependency tree (via serde_json).
nice tests. minor nit in comments, but don't feel strongly about it.