Make blank issue a more prominent option (#9860)

Collaborators keep creating issues with the templates when they really
should be doing triage and stuff themselves and we end up with a bunch
of boilerplate, incorrect labels, etc.

.github/ISSUE_TEMPLATE/config.yml

diff --git a/.github/ISSUE_TEMPLATE/config.yml b/.github/ISSUE_TEMPLATE/config.yml
index 7f14799..3eed5be 100644
--- a/.github/ISSUE_TEMPLATE/config.yml
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -1,4 +1,4 @@
-blank_issues_enabled: true
+blank_issues_enabled: false
 contact_links:
   - name: 📧 Send an email to our mailing list
     url: https://groups.google.com/forum/#!forum/iree-discuss

.github/ISSUE_TEMPLATE/z_blank_issue.yml

diff --git a/.github/ISSUE_TEMPLATE/z_blank_issue.yml b/.github/ISSUE_TEMPLATE/z_blank_issue.yml
new file mode 100644
index 0000000..86067ca
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/z_blank_issue.yml
@@ -0,0 +1,12 @@
+# This has a silly name to make it sort after the other issue templates
+name: 📄 Blank Issue
+description: If you know what you're doing (especially collaborators)
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Please remember to add appropriate labels, assignees, projects, etc.
+  - type: textarea
+    id: body
+    attributes:
+      label: "Issue body"