Add *.cmake to .gitignore

[goulven04]

To avoid having untracked files after launching cmake, when using as a GitHub sub module:

From the plugin root directory:

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
  (commit or discard the untracked or modified content in submodules)
        modified:   NeoRadarSDK (untracked content)

no changes added to commit (use "git add" and/or "git commit -a")

From the sdk sub module directory:

Cn branch main
Your branch is up to date with 'origin/main'.

Untracked files:
  (use "git add <file>..." to include in what will be committed)
        NeoRadarSDKConfig.cmake
        NeoRadarSDKConfigVersion.cmake
        NeoRadarSDKTargets.cmake

nothing added to commit but untracked files present (use "git add" to track)