fix: worker: Download proofs if PRU2 is enabled

[rjan90]

The lotus-worker does not check or download the params if Prove Replica Update tasks are enabled, meaning that you get an param-error if you for example a run a new 'PC1 / RU / PRU2' worker and a SnapDeal gets assigned to it. Reported in #8549.

Checklist

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• All commits have a clear commit message.
• The PR title is in the form of of <PR type>: <area>: <change being made>
  • example: fix: mempool: Introduce a cache for valid signatures
  • PR type: fix, feat, INTERFACE BREAKING CHANGE, CONSENSUS BREAKING, build, chore, ci, docs,perf, refactor, revert, style, test
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• This PR has tests for new functionality or change in behaviour
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[codecov]

Codecov Report

Merging #8555 (a50a20b) into master (1162b02) will decrease coverage by 0.04%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #8555      +/-   ##
==========================================
- Coverage   40.83%   40.78%   -0.05%     
==========================================
  Files         686      686              
  Lines       75587    75587              
==========================================
- Hits        30867    30831      -36     
- Misses      39391    39423      +32     
- Partials     5329     5333       +4     

Impacted Files	Coverage Δ
cmd/lotus-worker/main.go	0.00% <0.00%> (ø)
chain/events/message_cache.go	87.50% <0.00%> (-12.50%)	⬇️
chain/actors/builtin/miner/diff.go	48.52% <0.00%> (-10.30%)	⬇️
chain/events/events_called.go	83.90% <0.00%> (-4.40%)	⬇️
storage/wdpost_sched.go	77.45% <0.00%> (-3.93%)	⬇️
extern/sector-storage/sched.go	84.41% <0.00%> (-2.29%)	⬇️
extern/storage-sealing/currentdealinfo.go	70.17% <0.00%> (-1.76%)	⬇️
chain/stmgr/searchwait.go	67.30% <0.00%> (-1.29%)	⬇️
itests/kit/blockminer.go	88.58% <0.00%> (-1.09%)	⬇️
chain/vm/vm.go	61.63% <0.00%> (-1.07%)	⬇️
... and 13 more