upgrade to hashbrown 0.15.0

[rorosen]

Hashbrown 0.15.0 has reworked the entry API which requires the use of a raw entry builder to replace keys.

Closes #1597

Motivation

Upgrade to hashbrown 0.15.0

Solution

As a result of a reworked entry API in hashbrown 0.15.0, we cannot longer use the replace_key() function to replace an entry's key directly. This uses a raw entry builder for the HashMap instead.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.2%. Comparing base (2c97edd) to head (dd482eb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #1599   +/-   ##
=====================================
  Coverage   75.2%   75.2%           
=====================================
  Files         82      82           
  Lines       7336    7336           
=====================================
  Hits        5514    5514           
  Misses      1822    1822           

Files with missing lines	Coverage Δ
kube-runtime/src/scheduler.rs	94.8% <100.0%> (ø)

[rorosen]

hashbrown 0.15.0 also changed the default hasher from ahash to foldhash which uses the zlib license. However, it is approved for allowlist by cncf, so I added it to the allowlist.

[clux]

Hey, thanks a lot for this. Generally seems sensible, one quick Q.