Revert "Add missing visibility declarations (#548)"

[scpeters]

🦟 Bug fix

Revert #548 until we can figure out how to fix Windows CI.

Summary

This reverts commit a52a7d2.

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[codecov]

Codecov Report

Merging #553 (d607b2c) into main (a52a7d2) will not change coverage.
The diff coverage is n/a.

❗ Current head d607b2c differs from pull request most recent head 9f95163. Consider uploading reports for the commit 9f95163 to get more accurate results

@@           Coverage Diff           @@
##             main     #553   +/-   ##
=======================================
  Coverage   83.63%   83.63%           
=======================================
  Files          79       79           
  Lines       10213    10213           
=======================================
  Hits         8542     8542           
  Misses       1671     1671           

Files	Coverage Δ
profiler/src/RemoteryProfilerImpl.cc	84.13% <ø> (ø)
src/SignalHandler.cc	87.75% <ø> (ø)