libcbor: enable strictDeps

[erdnaxe]

Description of changes

Motivation: #178468

When building libcbor with strictDeps = true, the following error occurs:

[...]
-- Looking for ldexp
-- Looking for ldexp - found
-- Performing Test COMPILER_HAS_HIDDEN_VISIBILITY
-- Performing Test COMPILER_HAS_HIDDEN_VISIBILITY - Success
-- Performing Test COMPILER_HAS_HIDDEN_INLINE_VISIBILITY
-- Performing Test COMPILER_HAS_HIDDEN_INLINE_VISIBILITY - Success
-- Performing Test COMPILER_HAS_DEPRECATED_ATTR
-- Performing Test COMPILER_HAS_DEPRECATED_ATTR - Success
CMake Error at /nix/store/qlz2nfb0p7lbm22nqf9i9p35fz5z1xcj-cmake-3.25.3/share/cmake-3.25/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
  Could NOT find CMocka (missing: CMOCKA_LIBRARIES CMOCKA_INCLUDE_DIR)
Call Stack (most recent call first):
  /nix/store/qlz2nfb0p7lbm22nqf9i9p35fz5z1xcj-cmake-3.25.3/share/cmake-3.25/Modules/FindPackageHandleStandardArgs.cmake:600 (_FPHSA_FAILURE_MESSAGE)
  CMakeModules/FindCMocka.cmake:54 (find_package_handle_standard_args)
  test/CMakeLists.txt:3 (find_package)


-- Configuring incomplete, errors occurred!
See also "/build/source/build/CMakeFiles/CMakeOutput.log".

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.05 Release Notes (or backporting 22.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.