fix(async): fix another data race in the async package

[jsvisa]

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Uncomment one line below and remove others.

Bug fix
Feature
Documentation
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What does this PR do? Why is it needed?

datarace when run go test ./async/... -v -race:

WARNING: DATA RACE
Write at 0x00c000c06010 by goroutine 188:
  runtime.closechan()
      /usr/local/go/src/runtime/chan.go:357 +0x0
  github.com/prysmaticlabs/prysm/v5/async.Scatter.deferwrap1()
      /root/code/prysm/async/scatter.go:30 +0x33
  runtime.deferreturn()
      /usr/local/go/src/runtime/panic.go:602 +0x5d
  github.com/prysmaticlabs/prysm/v5/async_test.TestError()
      /root/code/prysm/async/scatter_test.go:93 +0xb5
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1689 +0x21e
  testing.(*T).Run.gowrap1()
      /usr/local/go/src/testing/testing.go:1742 +0x44

Previous read at 0x00c000c06010 by goroutine 189:
  runtime.chansend()
      /usr/local/go/src/runtime/chan.go:160 +0x0
  github.com/prysmaticlabs/prysm/v5/async.Scatter.func1()
      /root/code/prysm/async/scatter.go:45 +0x12c
  github.com/prysmaticlabs/prysm/v5/async.Scatter.gowrap3()
      /root/code/prysm/async/scatter.go:50 +0x4f

Goroutine 188 (running) created at:
  testing.(*T).Run()
      /usr/local/go/src/testing/testing.go:1742 +0x825
  testing.runTests.func1()
      /usr/local/go/src/testing/testing.go:2161 +0x85
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1689 +0x21e
  testing.runTests()
      /usr/local/go/src/testing/testing.go:2159 +0x8be
  testing.(*M).Run()
      /usr/local/go/src/testing/testing.go:2027 +0xf17
  main.main()
      _testmain.go:85 +0x2bd

Goroutine 189 (finished) created at:
  github.com/prysmaticlabs/prysm/v5/async.Scatter()
      /root/code/prysm/async/scatter.go:40 +0x3db
  github.com/prysmaticlabs/prysm/v5/async_test.TestError()
      /root/code/prysm/async/scatter_test.go:93 +0xb5
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1689 +0x21e
  testing.(*T).Run.gowrap1()
      /usr/local/go/src/testing/testing.go:1742 +0x44
==================
    testing.go:1398: race detected during execution of test
--- FAIL: TestError (0.00s)


WARNING: DATA RACE
Write at 0x00c000222870 by goroutine 82:
  runtime.mapassign_faststr()
      /usr/local/go/src/runtime/map_faststr.go:203 +0x0
  github.com/prysmaticlabs/prysm/v5/async.getChan()
      /root/code/prysm/async/multilock.go:120 +0x11e
  github.com/prysmaticlabs/prysm/v5/async.(*Lock).Lock()
      /root/code/prysm/async/multilock.go:43 +0x15d
  github.com/prysmaticlabs/prysm/v5/async.TestLockUnlock_DoesNotCleanIfHeldElsewhere.func2()
      /root/code/prysm/async/multilock_test.go:140 +0x104

Previous read at 0x00c000222870 by goroutine 81:
  github.com/prysmaticlabs/prysm/v5/async.TestLockUnlock_DoesNotCleanIfHeldElsewhere.func1()
      /root/code/prysm/async/multilock_test.go:135 +0xda

Goroutine 82 (running) created at:
  github.com/prysmaticlabs/prysm/v5/async.TestLockUnlock_DoesNotCleanIfHeldElsewhere()
      /root/code/prysm/async/multilock_test.go:138 +0x1bc
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1689 +0x21e
  testing.(*T).Run.gowrap1()
      /usr/local/go/src/testing/testing.go:1742 +0x44

Goroutine 81 (finished) created at:
  github.com/prysmaticlabs/prysm/v5/async.TestLockUnlock_DoesNotCleanIfHeldElsewhere()
      /root/code/prysm/async/multilock_test.go:128 +0x10c
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1689 +0x21e
  testing.(*T).Run.gowrap1()
      /usr/local/go/src/testing/testing.go:1742 +0x44

Fixes another data

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