Release 0.7.3 of the SPDX Maven Plugin

What's Changed

• The attribute downloadLocation is null when no information cannot be retrieved by @rogelio-o in #148
• Generate externalRefs with PURL by @rogelio-o in #150
• Dependency graph by @rogelio-o in #152
• Fix unit tests by @goneall in #156
• Bump org.apache.commons:commons-compress from 1.21 to 1.26.0 in /src/it/advanced by @dependabot in #154
• Fix another unit test variation by @goneall in #157

New Contributors

• @rogelio-o made their first contribution in #148

Full Changelog: v0.7.2...v0.7.3