fix: skip redundant AsyncAPI examples fetching during build (fixes #2015)

[gavin913427-hash]

What

Skip redundant AsyncAPI examples fetching during build when examples already exist.

Why

The scripts/fetch-asyncapi-example.js script was running on every build, even when examples already existed. This caused:

• Slower build times (downloading ZIP + parsing YAML files)
• Unnecessary network traffic
• Flaky builds when GitHub is unreachable

How

• Added a check to see if assets/examples/examples.json already exists
• If it does, skip the entire fetch/unzip/parse workflow
• To force a re-fetch, delete the assets/examples/ directory
• Also made tidyUp() safe by checking if the ZIP file exists before deleting

Changes

File	Change
scripts/fetch-asyncapi-example.js	Add existence check before fetching examples

Testing

# First build: fetches examples
npm run build

# Second build: skips fetch (fast)
npm run build
# Output: "Examples already exist, skipping fetch. Delete assets/examples/ to force re-fetch."

# Force re-fetch
rm -rf assets/examples/
npm run build

Fixes #2015

[changeset-bot]

🦋 Changeset detected

Latest commit: 8e2c1bc

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@asyncapi/cli	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud