Caplin: to set boundaries - no how much goroutines can be spawned by for loop

[AskAlexSharov]

Found many patterns like:

wg := WaitGroup{}
for {
  wg.Add(1)
  go func() {
     defer wg.Done(1)
  }
}
wg.Wait()

Examples:
getDutiesProposer
connectWithAllPeers
batchVerifyAttestations
VerifyAgainstIdentifiersAndInsertIntoTheBlobStore

This pattern spawns unlimited amount of goroutines. All "unlimited" things are bad - because:

• because we have limited cpus/ram/disk/etc...
• even if today some loop doesn't spawn much goroutines - future PR's or future bugs - may change it and we will not notice
• some "for loops" are run in-parallel - means it's will be hard for us to reproduce "worst case scenario" - where N loops spawning much goroutines in same time.

---

let's replace it by next pattern:

g := &errgroup.Group{}
g.SetLimit(runtime.GOMAXPROCS(-1))
for {
  g.Go(func() error {
  })
}
if err := g.Wait(); err != nil {
    return err 
})

Can set any limit you like.