Update default deny configuration keys across integrations

Replace 'deny_user_default' with 'deny_default' in GitLab, GitHub, and PDB integration files for consistency.

src/integrations/integr_github.rs

@@ -202,5 +202,5 @@ available:
   when_isolated_possible: true
 confirmation:
   ask_user_default: ["gh * delete", "gh * close"]
-  deny_user_default: ["gh auth token"]
+  deny_default: ["gh auth token"]
 "#;

src/integrations/integr_gitlab.rs

@@ -200,5 +200,5 @@ available:
   when_isolated_possible: true
 confirmation:
   ask_user_default: ["glab * delete"]
-  deny_user_default: ["glab auth token"]
+  deny_default: ["glab auth token"]
 "#;

src/integrations/integr_pdb.rs

@@ -389,5 +389,5 @@ available:
   when_isolated_possible: true
 confirmation:
   ask_user_default: []
-  deny_user_default: []
+  deny_default: []
 "#;