feat: add hepmc2 and hepmc3 version pins

[chrisburr]

Summary

• Add hepmc2 pin at 2.06 (latest: 2.06.11)
• Add hepmc3 pin at 3.3 (latest: 3.3.1)

These pins match the upper_bound='x.x' run_exports being added in:

• feat: modernize recipe, add run_exports hepmc2-feedstock#13
• feat: add run_exports and modernize recipe hepmc3-feedstock#34

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe/meta.yaml:

• ℹ️ The recipe is not parsable by parser conda-recipe-manager. The recipe can only be automatically migrated to the new v1 format if it is parseable by conda-recipe-manager.

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/22156066791. Examine the logs at this URL for more detail.}