Publish modules with appropriate stability suffix.

The topmost README.md contains a list of all of the modules in this repo under "Provided Libraries". This table contains each library name (linked to the module) and a "status" column, which is a stability field (one of alpha, beta, or stable).

However, because we publish all modules at the same time with the same version number, they all result in an -alpha suffix. This is confusing because beta modules have an alpha suffix (example), as does the stable one (example).

However, modules that don't yet have a otel.stable=true in their gradle.properties file will publish with the -alpha suffix even when they are marked as beta (example). It seems that the stable artifacts do actually have the -alpha suffix omitted.

It would be awesome if we could find a way to declare the stability of each module and publish its artifacts with the appropriate suffix (or none for stable).

(Also related to #2077)

Start with the top-level README.md module table and compare each module's status with its gradle.properties, especially the otel.stable=true setting. Trace the existing publication configuration to see how the version suffix is selected. Done means alpha, beta, and stable modules publish with matching suffixes, with stable artifacts omitting the suffix.