fix(metrics): do not use shared DefaultRegistry and fix wg.Done call

[ajcasagrande]

If your build fails due to your commit message not passing the build checks, please review the guidelines here: https://github.com/edgexfoundry/go-mod-bootstrap/blob/main/.github/Contributing.md

PR Checklist

Please check if your PR fulfills the following requirements:

• I am not introducing a breaking change (if you are, flag in conventional commit message with BREAKING CHANGE: describing the break)
• I am not introducing a new dependency (add notes below if you are)
• I have added unit tests for the new feature or bug fix (if not, why?)
• I have fully tested (add details below) this the new feature or bug fix (if not, why?)
  I have only fully tested via the unit tests, and not under a real working scenario
• I have opened a PR for the related docs change (if not, why?) N/A

Testing Instructions

• checkout current main branch
• run: go test github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/metrics -test.count 10
• expect FAIL
• checkout this PR
• run go test github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/metrics -test.count 10
• expect PASS

New Dependency Instructions (If applicable)

I have verified that this Fixes #458 on my local machine

[codecov-commenter]

Codecov Report

Merging #543 (7010ea7) into main (4bbc8c1) will not change coverage.
The diff coverage is 100.00%.

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@@           Coverage Diff           @@
##             main     #543   +/-   ##
=======================================
  Coverage   57.32%   57.32%           
=======================================
  Files          27       27           
  Lines        2219     2219           
=======================================
  Hits         1272     1272           
  Misses        865      865           
  Partials       82       82           

Impacted Files	Coverage Δ
bootstrap/metrics/manager.go	89.42% <100.00%> (ø)

[cloudxxx8]

LGTM