Issue forms: remove title from bug template

Signed-off-by: Ekaterina Gerasimova <kittykat3756@gmail.com>

.github/ISSUE_TEMPLATE/bug-desktop.yml

@@ -1,6 +1,5 @@
 name: Bug report for the Element desktop app (not in a browser)
 description: File a bug report if you are using the desktop Element application.
-title: "[Bug]: "
 labels: [T-Defect, triage]
 assignees:
   -   

.github/ISSUE_TEMPLATE/bug-web.yml

@@ -1,6 +1,5 @@
 name: Bug report for Element Web (in browser)
 description: File a bug report if you are using Element in a web browser like Firefox, Chrome, Edge, and so on.
-title: "[Bug]: "
 labels: [T-Defect, triage]
 assignees:
   -