fix: post workers: check proving params on startup

[magik6k]

PoSt workers are doing snarks, so they need proof params

[codecov]

Codecov Report

Merging #8736 (7d7ecb5) into master (7836e20) will increase coverage by 0.04%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #8736      +/-   ##
==========================================
+ Coverage   40.84%   40.88%   +0.04%     
==========================================
  Files         692      692              
  Lines       76177    76177              
==========================================
+ Hits        31112    31144      +32     
+ Misses      39688    39666      -22     
+ Partials     5377     5367      -10     

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%> (-1.96%)	⬇️
miner/miner.go	55.73% <0.00%> (-0.99%)	⬇️
storage/wdpost_changehandler.go	98.11% <0.00%> (-0.48%)	⬇️
chain/sync_manager.go	74.22% <0.00%> (-0.32%)	⬇️
chain/stmgr/call.go	69.18% <0.00%> (ø)
node/impl/storminer.go	23.78% <0.00%> (+0.30%)	⬆️
chain/messagepool/selection.go	83.84% <0.00%> (+0.38%)	⬆️
... and 9 more