Needed to maintain listing in k6 Extensions Registry

[javaducky]

We've recently updated the requirements for maintaining an extension within the listing on our site. As such, please address the following items to maintain your listing within the registry:

• requires at least one versioned release
• needs to build with a recent version of k6; minimum v0.43

For more information on these and other listing requirements, please take a look at the registry requirements.

[pmalhaire]

@javaducky done and updated README

[pmalhaire]

Release :

• https://github.com/pmalhaire/xk6-mqtt/releases/tag/v0.39.2
• builds with k6 v0.43

[javaducky]

@pmalhaire thank you for looking into this. Could you update the go.mod to require a recent version of k6? Latest release of k6 is v0.45.0, but minimum requirement is v0.43.0.

[pmalhaire]

updated go.mod in main branch to require k6 v0.45.0