lint: enable intrange linter (#7331)

Enable intrange linter to enforce modern Go range syntax over
traditional for loops, by converting:

for i := 0; i < n; i++

to:

for i := range n

Adding type conversions where needed for compatibility
with existing uint64 parameters.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>

plugin/erratic/erratic.go

@@ -57,7 +57,7 @@ func (e *Erratic) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg
 		rr.Header().Name = state.QName()
 		m.Answer = append(m.Answer, &rr)
 		if e.large {
-			for i := 0; i < 29; i++ {
+			for range 29 {
 				m.Answer = append(m.Answer, &rr)
 			}
 		}