hotfix: don't override version in maven publishing configuration

[jacob-derynk]

Problem

Release publish was failing on CI with:
"The value for extension 'mavenPublishing' property 'version$plugin' is
final and cannot be changed any further."

vanniktech/gradle-maven-publish-plugin 0.34.0 automatically reads
VERSION_NAME
from Gradle project properties and finalizes the version field during plugin
configuration. The explicit coordinates(version = ...) call then tried to
overwrite an already-finalized value.

Snapshot publish worked because it doesn't pass -PVERSION_NAME, so the
plugin
never finalized the property.

Fix

• Remove version from coordinates() in both library build files — the
  plugin
  reads VERSION_NAME natively.
• Add VERSION_NAME=2.X.X-SNAPSHOT to gradle.properties as the default for
  snapshot builds. Release CI overrides it with -PVERSION_NAME=x.y.z.