This change added the spark2 root pom profile -

<activation>
    <activeByDefault>true</activeByDefault>
    <property>
        <name>!spark-version</name>
    </property>
</activation>

Since most users (and I think the CI) do not build with -Dspark-version set to a valid value, this spark2 profile is always active. I confirmed this via ./mvnw help:active-profiles

Issue

The spark2 profile skips the enforcer check by default -

<configuration>
     <skip>true</skip>

Due to this maven enforcer has not been executing on the CI jobs

For example, the #26378 PR updates logback-core to a version not compatible with presto-main-base but the CI did not flag this