Multiple fixes

[kostko]

• go/worker/common: Refresh current epoch for suspended runtimes
• go/runtime/registry: Allow client nodes without runtimes
• go/oasis-node: Also migrate old Testnet seed node address
• go/oasis-node: Migrate validators without runtimes to validator mode
• go/p2p: Stop spamming logs with "peer already connected"

[codecov]

Codecov Report

Merging #5400 (1d12295) into master (9ed07e5) will decrease coverage by 0.15%.
Report is 8 commits behind head on master.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master    #5400      +/-   ##
==========================================
- Coverage   66.33%   66.18%   -0.15%     
==========================================
  Files         534      534              
  Lines       56307    56322      +15     
==========================================
- Hits        37349    37279      -70     
- Misses      14548    14614      +66     
- Partials     4410     4429      +19     

Files	Coverage Δ
go/consensus/cometbft/apps/beacon/beacon.go	75.67% <100.00%> (-2.11%)	⬇️
go/oasis-node/cmd/config/migrate/migrate.go	70.74% <100.00%> (+0.76%)	⬆️
go/p2p/peermgmt/connector.go	98.11% <ø> (-1.89%)	⬇️
go/runtime/registry/config.go	67.70% <66.66%> (+0.62%)	⬆️
go/worker/keymanager/worker.go	75.02% <80.00%> (-0.63%)	⬇️
go/worker/common/committee/node.go	59.91% <50.00%> (-1.75%)	⬇️

... and 40 files with indirect coverage changes