Update CODEOWNERS (#8728)

Adding @JPPhoto to CODEOWNERS

Co-authored-by: Lincoln Stein <[email protected]>

Author: JPPhoto

.github/CODEOWNERS

@@ -6,7 +6,7 @@
 /mkdocs.yml @lstein @blessedcoolant  
 
 # nodes
-/invokeai/app/ @blessedcoolant @lstein 
+/invokeai/app/ @blessedcoolant @lstein @JPPhoto
 
 # installation and configuration
 /pyproject.toml  @lstein @blessedcoolant  
@@ -21,7 +21,7 @@
 /invokeai/frontend @blessedcoolant  @lstein  
 
 # generation, model management, postprocessing
-/invokeai/backend  @lstein @blessedcoolant     
+/invokeai/backend  @lstein @blessedcoolant @JPPhoto
 
 # front ends
 /invokeai/frontend/CLI @lstein