[D7] Allow modules to opt in to testing against max PHP version: OPT_IN_TEST_MAX_PHP

Migrated issue

Reported by: poker10

Related to !174 (merged) !173 (merged) !166 (merged)

Problem/Motivation

This is a D7 backport of #3398709: Allow modules to opt in to testing against max PHP version: OPT_IN_TEST_MAX_PHP

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Related issue: Issue #3398709