fix: remove redundant const qualifier on reference type

[rbqvq]

Description

CLANGARM64 emits -Wignored-reference-qualifiers
warning because 'const' on a reference type has no effect.

Removing it cleans up the build output and improves compatibility with LLVM toolchains.

Type of Change

• feat: New feature (non-breaking change which adds functionality)
• fix: Bug fix (non-breaking change which fixes an issue)
• docs: Documentation only changes
• style: Changes that do not affect the meaning of the code (white-space, formatting, missing semicolons, etc.)
• refactor: Code change that neither fixes a bug nor adds a feature
• perf: Code change that improves performance
• test: Adding missing tests or correcting existing tests
• build: Changes that affect the build system or external dependencies
• ci: Changes to CI configuration files and scripts
• chore: Other changes that don't modify src or test files
• revert: Reverts a previous commit
• BREAKING CHANGE: Introduces a breaking change (can be combined with any type above)

Checklist

• Code follows the style guidelines of this project
• Code has been self-reviewed
• Code has been commented, particularly in hard-to-understand areas
• Code docstring/documentation-blocks for new or existing methods/components have been added or updated
• Unit tests have been added or updated for any new or modified functionality

AI Usage

• None: No AI tools were used in creating this PR
• Light: AI provided minor assistance (formatting, simple suggestions)
• Moderate: AI helped with code generation or debugging specific parts
• Heavy: AI generated most or all of the code changes

[rbqvq]

Original log here:

Warning: C:/a/Sunshine/Sunshine/third-party/libdisplaydevice/src/windows/settings_utils.cpp:45:77: warning: 'const' qualifier on reference type 'std::add_lvalue_reference_t<bool (const EnumeratedDevice &)>' (aka 'bool (&)(const EnumeratedDevice &)') has no effect [-Wignored-reference-qualifiers]
   45 |     std::set<std::string> getDeviceIds(const EnumeratedDeviceList &devices, const std::add_lvalue_reference_t<bool(const EnumeratedDevice &)> &predicate) {
      |  

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.12%. Comparing base (825b484) to head (2470458).
⚠️ Report is 32 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #198   +/-   ##
=======================================
  Coverage   93.12%   93.12%           
=======================================
  Files          34       34           
  Lines        2123     2123           
  Branches     1086     1086           
=======================================
  Hits         1977     1977           
+ Misses         82       75    -7     
- Partials       64       71    +7     

Flag	Coverage Δ
Linux	93.73% <ø> (ø)
Windows	92.80% <100.00%> (ø)
macOS	74.20% <ø> (ø)

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

Files with missing lines	Coverage Δ
src/windows/settings_utils.cpp	96.50% <100.00%> (ø)

... and 1 file with indirect coverage changes

[ReenigneArcher]

Failing test is not a result of these changes. PR welcome if you have a fix for it.

[rbqvq]

Thanks, I think I don't have any fix plan :(