ignore_php_platform_requirements top-level option for .laminas-ci.json is wrong in the read me.

[tyrsson]

Bug Report

Q	A
Version(s)	1.43.0

Summary

If you use the value given in the README.md which is "ignore_php_platform_requirement" job matrix generation fails.

Just need to add a "s".

"ignore_php_platform_requirements".

I'll open a PR soon as I get time unless someone gets to it first. Just did not want to forget it.

Current behavior

See summary

How to reproduce

Use the option as provided in the read me.

Expected behavior