Require device diagnostics for all issues and PRs (#4247)

Author: puddly

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -64,6 +64,8 @@ body:
         
         You can find the diagnostics information by going to the device page, clicking the three dots, and then by clicking on "Download diagnostics".
         Drag-and-drop the downloaded file into the textbox below.
+    validations:
+      required: true
   - type: textarea
     attributes:
       label: Device signature

.github/ISSUE_TEMPLATE/device_support_request.yml

@@ -53,6 +53,8 @@ body:
         
         You can find the diagnostics information by going to the device page, clicking the three dots, and then by clicking on "Download diagnostics".
         Drag-and-drop the downloaded file into the textbox below.
+    validations:
+      required: true
   - type: textarea
     attributes:
       label: Device signature

.github/PULL_REQUEST_TEMPLATE.md

@@ -13,6 +13,18 @@
 -->
 
 
+## Device diagnostics
+<!--
+  Diagnostics data is used by ZHA unit tests to make sure quirks create the expected
+  entities and we do not have regressions. For all new quirks, we require device
+  diagnostics.
+
+  You can find the diagnostics information by going to the device page, clicking the
+  three dots, and then by clicking on "Download diagnostics". Drag-and-drop the
+  downloaded file into this section.
+-->
+
+
 ## Checklist
 <!--
   Put an 'x' in all boxes that apply.
@@ -22,3 +34,4 @@
 - [ ] The changes are tested and work correctly
 - [ ] `pre-commit` checks pass / the code has been formatted using Black
 - [ ] Tests have been added to verify that the new code works
+- [ ] Device diagnostics data has been attached