[release-0.8] cpuallocator: fix cpu priority discovery

[marquiz]

The CPU priorities were discovered correctly but not stored in the cpuallocator so they were effectively discarded.

(cherry picked from commit daa821d)

Backports #971

[codecov-commenter]

Codecov Report

Merging #978 (46ddbbd) into release-0.8 (7d464f9) will decrease coverage by 1.73%.
The diff coverage is 100.00%.

@@               Coverage Diff               @@
##           release-0.8     #978      +/-   ##
===============================================
- Coverage        33.68%   31.95%   -1.73%     
===============================================
  Files               61       65       +4     
  Lines             9156     9835     +679     
===============================================
+ Hits              3084     3143      +59     
- Misses            5789     6404     +615     
- Partials           283      288       +5     

Impacted Files	Coverage Δ
pkg/cpuallocator/allocator.go	48.32% <100.00%> (+0.15%)	⬆️
pkg/cgroups/cgroupstats.go	0.00% <0.00%> (ø)
...source-manager/policy/builtin/dynamic-pools/cpu.go	0.00% <0.00%> (ø)
...ce-manager/policy/builtin/dynamic-pools/metrics.go	0.00% <0.00%> (ø)
...urce-manager/policy/builtin/dynamic-pools/flags.go	46.42% <0.00%> (ø)
...source-manager/policy/builtin/dynamic-pools/dyp.go	9.35% <0.00%> (ø)

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[askervin]

LGTM

[marquiz]

Plz push the merge button 🥺