COMP: Skip dot-directories when scanning for ITK modules

GLOB_RECURSE matches itk-module.cmake at any depth, so a nested source
tree under a dot-directory is absorbed as a set of duplicate modules.
Dot-directories hold tool state by convention -- git worktrees, editor
and agent directories, and environment or cache trees such as the
in-source .pixi directory created by ITK's own build tooling -- and
.gitignore already declares several of them non-source.

One affected tree reported 984 modules where 204 exist, and failed
building the stale duplicates.

Author: hjmjohnson

CMake/ITKModuleEnablement.cmake

@@ -8,6 +8,8 @@ macro(itk_module_load_dag)
     RELATIVE "${ITK_SOURCE_DIR}"
     "${ITK_SOURCE_DIR}/*/*/*/itk-module.cmake" # grouped modules
   )
+  # Dot-directories hold tool state (worktrees, environments, caches), not ITK source.
+  list(FILTER meta EXCLUDE REGEX "(^|/)\\.")
   foreach(f ${meta})
     include(${ITK_SOURCE_DIR}/${f})
     list(APPEND ITK_MODULES_ALL ${itk-module})