[c++] Fix some build errors for Docker

[johnkerl]

Issue and/or context: Found in Docker builds for cloud deploys, using 1.15.4. Compling fine on our CI though. See #3154.

Changes:

Notes for Reviewer:

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.31%. Comparing base (4e92187) to head (5d89309).
Report is 1 commits behind head on release-1.15.

Additional details and impacted files

@@               Coverage Diff                @@
##           release-1.15    #3620      +/-   ##
================================================
+ Coverage         86.26%   86.31%   +0.04%     
================================================
  Files                55       55              
  Lines              6378     6378              
================================================
+ Hits               5502     5505       +3     
+ Misses              876      873       -3     

Flag	Coverage Δ
python	86.31% <ø> (+0.04%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
python_api	86.31% <ø> (+0.04%)	⬆️
libtiledbsoma	∅ <ø> (∅)

[github-actions]

The backport to release-1.15 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-release-1.15 release-1.15
# Navigate to the new working tree
cd .worktrees/backport-release-1.15
# Create a new branch
git switch --create backport-3620-to-release-1.15
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 fdb092111ffe21134b7b2814d59cfd3166d385d8
# Push it to GitHub
git push --set-upstream origin backport-3620-to-release-1.15
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release-1.15

Then, create a pull request where the base branch is release-1.15 and the compare/head branch is backport-3620-to-release-1.15.