No longer compatible with Java 8

[ryanb93]

I receive the following error when attempting to update to 0.1.0

      > No matching variant of org.ec4j.gradle:editorconfig-gradle-plugin:0.1.0 was found. The consumer was configured to find a library for use during runtime, compatible with Java 11, packaged as a jar, and its dependencies declared externally, as well as attribute 'org.gradle.plugin.api-version' with value '8.6' but:
          - Variant 'apiElements' capability org.ec4j.gradle:editorconfig-gradle-plugin:0.1.0 declares a library, packaged as a jar, and its dependencies declared externally:
              - Incompatible because this component declares a component for use during compile-time, compatible with Java 16 and the consumer needed a component for use during runtime, compatible with Java 11
              - Other compatible attribute:
                  - Doesn't say anything about org.gradle.plugin.api-version (required '8.6')

However documentation suggests it works with Java 8. I am in a position where I trying to migrate to Gradle 8, 0.0.3 is incompatible with it and 0.1.0 requires a Java version upgrade which is not currently possible.

[ppalaga]

Yeah, it looks like we set Java 16 around here:

https://github.com/ec4j/editorconfig-gradle-plugin/pull/16/files#diff-c0dfa6bc7a8685217f70a860145fbdf416d449eaff052fa28352c5cec1a98c06R37-R47

I wonder whether Java 8 would work there too? A PR would be welcome.