Follow directory symlinks in auto deploying manifests (#9288)

[rorosen]

Proposed Changes

I use k3s in NixOS and am affected by #9288, the auto-deploy controller does not follow symlinked directories. This is a little annoying since it's pretty normal to link large parts of the filesystem in NixOS.

Types of Changes

The deploy controller will now follow top-level symlink directories.

Verification

I tested the changes locally.

Testing

I couldn't find unit tests for the deploy controller and hence don't know what would be the best place for tests. Happy to add a test if required.

Linked Issues

• Auto-Deploying Manifests ignores symlinked directories #9288

User-Facing Change

Symlinked sub-directories are now respected when scanning Auto-Deploying Manifests (AddOns) 

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 13 lines in your changes are missing coverage. Please review.

Project coverage is 43.55%. Comparing base (fe7d114) to head (1aac62d).
Report is 3 commits behind head on master.

Files	Patch %	Lines
pkg/deploy/controller.go	0.00%	12 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #10049      +/-   ##
==========================================
- Coverage   48.92%   43.55%   -5.37%     
==========================================
  Files         158      158              
  Lines       14032    14045      +13     
==========================================
- Hits         6865     6118     -747     
- Misses       5885     6762     +877     
+ Partials     1282     1165     -117     

Flag	Coverage Δ
e2etests	36.37% <0.00%> (-10.41%)	⬇️
inttests	37.06% <0.00%> (?)
unittests	16.58% <ø> (ø)

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[dereknola]

BTRFS E2e failure can be ignored. Solved by #10057. You can rebase master if you really want to see "all green", but its not required 😄