fix: Display a warning but continue execution when dumping an exception and unable to find related issues

Occasionally, when failing to `brew install` or `brew upgrade` a formula, users will get an error message and the last line of it will be:
```
Error: Validation Failed: [{"message"=>"The listed users and repositories cannot be searched either because the resources do not exist or you do not have permission to view them.", "resource"=>"Search", "field"=>"q", "code"=>"invalid"}]
```

Here's an old public example: https://gitlab.com/tabos/rogerrouter/-/issues/21

At Square, this error can be caused by a transient issue with a user's GitHub credentials.

My proposal is that any error which prevents `brew` from showing related issues should:
1. Not cause `brew` to exit early (vs. printing diagnostic checks and doing any other cleanup)
2. Be clearly differentiated from the original failure (so it doesn't become a red herring for users troubleshooting their broken formula)

Library/Homebrew/exceptions.rb

@@ -490,8 +490,8 @@ class BuildError < RuntimeError
   sig { returns(T::Array[T.untyped]) }
   def fetch_issues
     GitHub.issues_for_formula(formula.name, tap: formula.tap, state: "open", type: "issue")
-  rescue GitHub::API::RateLimitExceededError => e
-    opoo e.message
+  rescue GitHub::API::Error => e
+    opoo "Unable to query GitHub for recent issues on the tap\n#{e.message}"
     []
   end