ci: Fix issue response script (#24891)

This PR fixes the issue response script.

There were a number of things preventing it from working:

- The directory name used in the GitHub Action did not match the one on
disk.
  - The script has been moved accordingly
- `ts-node` does not support ESM.
- `ts-node` seems unmaintained, so I changed the script to be plain JS
that is type-checked with TypeScript.
- The data being sent to the Slack API was invalid:
- Each section block can only have a maximum of 3000 characters in the
`text` field, so we need to break up the issue list across multiple
sections.
- We needed to escape `&`, `<`, and `>` characters in the issue titles.

Release Notes:

- N/A

script/issue_response/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "$schema": "https://json.schemastore.org/tsconfig",
+  "extends": ["@tsconfig/node20/tsconfig.json", "@tsconfig/strictest/tsconfig.json"],
+  "compilerOptions": {
+    "checkJs": true,
+    "noEmit": true
+  },
+  "include": ["main.js"]
+}