v2.8.4-rc4

What's Changed

• Update upload/download-artifact actions by @milesgranger in #170
• Add more feature configuration options by @milesgranger in #174
• Fix blosc2 upgrade API changes by @milesgranger in #176
• Expose linking flexibility for xz, gzip/deflate from libcramjam by @milesgranger in #175
• Remove pypy3.9 from CI by @milesgranger in #177
• Exclude benchmarks from builds by @milesgranger in #179
• Add wasm32-emscripten builds by @milesgranger in #181
• Add experimental igzip cramjam.experimental.igzip by @milesgranger in #182

Full Changelog: v2.8.4-rc3...v2.8.4-rc4