chore: 0.5.1 release proposal

[dyladan]

The draft release notes: https://github.com/open-telemetry/opentelemetry-js/releases/tag/untagged-159da650fce080536826

[codecov-io]

Codecov Report

Merging #883 into master will increase coverage by 0.05%.
The diff coverage is 38.46%.

@@            Coverage Diff             @@
##           master     #883      +/-   ##
==========================================
+ Coverage   92.41%   92.47%   +0.05%     
==========================================
  Files         244      246       +2     
  Lines       10785    10890     +105     
  Branches     1049     1065      +16     
==========================================
+ Hits         9967    10070     +103     
- Misses        818      820       +2     

Impacted Files	Coverage Δ
packages/opentelemetry-api/src/version.ts	0.00% <0.00%> (ø)
packages/opentelemetry-base/src/version.ts	0.00% <0.00%> (ø)
...s/opentelemetry-context-async-hooks/src/version.ts	0.00% <0.00%> (ø)
packages/opentelemetry-context-base/src/version.ts	0.00% <0.00%> (ø)
...opentelemetry-context-zone-peer-dep/src/version.ts	0.00% <0.00%> (ø)
...kages/opentelemetry-exporter-jaeger/src/version.ts	0.00% <0.00%> (ø)
...s/opentelemetry-exporter-prometheus/src/version.ts	0.00% <0.00%> (ø)
...kages/opentelemetry-exporter-zipkin/src/version.ts	0.00% <0.00%> (ø)
packages/opentelemetry-metrics/src/version.ts	0.00% <0.00%> (ø)
packages/opentelemetry-node/src/version.ts	0.00% <0.00%> (ø)
... and 40 more