fix: catch no updates CFN error and fix CFN poller hang

[edwardfoyle]

Description of changes

Issue #, if available

Description of how you validated changes

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

Merging #7548 (bb1a342) into master (0521fc0) will decrease coverage by 8.31%.
The diff coverage is 59.76%.

@@            Coverage Diff             @@
##           master    #7548      +/-   ##
==========================================
- Coverage   61.07%   52.76%   -8.32%     
==========================================
  Files         222      523     +301     
  Lines       11479    26157   +14678     
  Branches     2250     5119    +2869     
==========================================
+ Hits         7011    13802    +6791     
- Misses       4160    11385    +7225     
- Partials      308      970     +662     

Impacted Files	Coverage Δ
...psync-simulator/src/data-loader/dynamo-db/index.ts	10.86% <0.00%> (+10.86%)	⬆️
...amplify-appsync-simulator/src/data-loader/index.ts	60.00% <ø> (ø)
...fy-appsync-simulator/src/schema/directives/auth.ts	20.28% <0.00%> (ø)
...ages/amplify-appsync-simulator/src/schema/index.ts	19.40% <0.00%> (ø)
...rver/subscription/mqtt-server/abstract-listener.ts	85.00% <ø> (ø)
...c/server/subscription/mqtt-server/trie-listener.ts	36.66% <ø> (ø)
...ulator/src/server/subscription/mqtt-server/util.ts	33.33% <ø> (ø)
...s/amplify-appsync-simulator/src/type-definition.ts	100.00% <ø> (ø)
...psync-simulator/src/utils/expose-graphql-errors.ts	57.14% <ø> (ø)
...ator/src/server/subscription/mqtt-server/client.ts	8.97% <8.97%> (ø)
... and 546 more

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[github-actions]

👋 Hi, this pull request was referenced in the v5.0.1 release!

Check out the release notes here https://github.com/aws-amplify/amplify-cli/releases/tag/v5.0.1.