bump nim-confutils to silence more BareExcept warnings

[tersec]

Before (#4661 (comment))

$ cat ~/all.txt all.txt  | grep BareExcept | sort | uniq -c | sort -rn
     45 nimbus-eth2/vendor/nim-unittest2/unittest2.nim(821, 5) Warning: catch a more precise Exception deriving from CatchableError or Defect. [BareExcept]
      7 nimbus-eth2/vendor/nim-unittest2/unittest2.nim(981, 5) Warning: catch a more precise Exception deriving from CatchableError or Defect. [BareExcept]
      2 nimbus-eth2/ncli/ncli_testnet.nim(640, 5) Warning: catch a more precise Exception deriving from CatchableError or Defect. [BareExcept]
      2 nimbus-eth2/ncli/ncli_testnet.nim(522, 3) Warning: catch a more precise Exception deriving from CatchableError or Defect. [BareExcept]
      1 nimbus-eth2/tests/test_keymanager_api.nim(327, 3) Warning: The bare except clause is deprecated; use `except CatchableError:` instead [BareExcept]
      1 nimbus-eth2/tests/test_keymanager_api.nim(299, 3) Warning: catch a more precise Exception deriving from CatchableError or Defect. [BareExcept]
      1 nimbus-eth2/tests/test_keymanager_api.nim(183, 3) Warning: catch a more precise Exception deriving from CatchableError or Defect. [BareExcept]
      1 nimbus-eth2/beacon_chain/eth1/deposit_contract.nim(202, 3) Warning: catch a more precise Exception deriving from CatchableError or Defect. [BareExcept

All of these are gone now. They were artifacts of nim-confutils unconditionally re-enabling this warning after disabling it rather than restore the previous state.

The underlying code is still there, and eventually probably worth fixing, but they can be fixed when the appropriate tools become available, rather than spamming unactionable warnings until then.

[github-actions]

Unit Test Results

         9 files  ±0    1 068 suites  ±0   36m 21s ⏱️ + 2m 45s
  3 648 tests ±0    3 369 ✔️ ±0  279 💤 ±0  0 ❌ ±0 
15 569 runs  ±0  15 264 ✔️ ±0  305 💤 ±0  0 ❌ ±0 

Results for commit 708907e. ± Comparison against base commit 82bf949.