[clad] Bump to clad v2.2.

Clad 2.2, delivers improvements to differentiation pipelines, feature coverage,
and language compatibility. It now supports clang versions 11–21, includes
better handling of pointer, tensor, and reference types, and adds conversion
operator and `std::reference_wrapper` support. Forward mode gains experimental
OpenMP differentiation, while reverse mode introduces loop checkpointing,
elidable reverse passes, and enhanced handling of complex expressions and memory
operations. CUDA support expands with new Thrust operations, device vector
support, and a logistic regression demo. The release also improves thread safety
through lock-controlled tape access, refines error handling and diagnostics, and
simplifies attribute-based memory management.

Author: vgvassilev

interpreter/cling/tools/plugins/clad/CMakeLists.txt

@@ -74,7 +74,7 @@ if (DEFINED CLAD_SOURCE_DIR)
   list(APPEND _clad_extra_settings SOURCE_DIR ${CLAD_SOURCE_DIR})
 else()
   list(APPEND _clad_extra_settings GIT_REPOSITORY https://github.com/vgvassilev/clad.git)
-  list(APPEND _clad_extra_settings GIT_TAG v2.1)
+  list(APPEND _clad_extra_settings GIT_TAG v2.2)
 endif()
 
 ## list(APPEND _clad_patches_list "patch1.patch" "patch2.patch")