Release v0.39.0

• Bumped OpenTelemetry Collector to v0.39.0 (#579, #578, @VineethReddy02 )
• Upgrade path for Instrumentation kind (#548, @pavolloffay)
• Auto-instrumentation support for python (#532, @anuraaga)
• Support for PodSecurityContext in OpenTelemetry collector (#469, @ekarlso)
• Java auto-instrumentation support is bumped to 1.7.2 (#549, @pavolloffay)
• Auto-instrumentation support for nodejs (#507, @anuraaga)
• Sampler configuration support in instrumentation kind (#514, @pavolloffay)