2.8.0

Various fixes & improvements

• profiler_id uses underscore (#3249) by @Zylphrex
• Don't send full env to subprocess (#3251) by @kmichel-aiven
• Stop using Hub in HttpTransport (#3247) by @szokeasaurusrex
• Remove ipdb from test requirements (#3237) by @rominf
• Avoid propagation of empty baggage (#2968) by @hartungstenio
• Add entry point for SentryPropagator (#3086) by @mender
• Bump checkouts/data-schemas from 8c13457 to 88273a9 (#3225) by @dependabot