chore: 0.21.0 release proposal

[github-actions]

This is an auto-generated release PR. If additional changes need to be incorporated before the release, the CHANGELOG must be updated manually.

Merging this PR will automatically release all packages to NPM.

[Flarna]

Not directly related to thi PR. Once again it seems we miss updating examples. e.g. express is still refering to 0.15.0.
Maybe we should simply remove them as there is no CI testing them nor is there someone having the time to keep them up and running. I guess it's quite a bad experience for users to start with non working examples.

[codecov]

Codecov Report

Merging #536 (c6077cf) into main (3ea5298) will increase coverage by 0.05%.
The diff coverage is 40.00%.

❗ Current head c6077cf differs from pull request most recent head a49796c. Consider uploading reports for the commit a49796c to get more accurate results

@@            Coverage Diff             @@
##             main     #536      +/-   ##
==========================================
+ Coverage   94.82%   94.88%   +0.05%     
==========================================
  Files         157      162       +5     
  Lines        9862     9986     +124     
  Branches      957      986      +29     
==========================================
+ Hits         9352     9475     +123     
- Misses        510      511       +1     

Impacted Files	Coverage Δ
...ntelemetry-resource-detector-github/src/version.ts	0.00% <0.00%> (ø)
...apackages/auto-instrumentations-web/src/version.ts	0.00% <0.00%> (ø)
...opentelemetry-id-generator-aws-xray/src/version.ts	0.00% <0.00%> (ø)
...s/opentelemetry-propagator-aws-xray/src/version.ts	0.00% <0.00%> (ø)
...metry-propagator-grpc-census-binary/src/version.ts	0.00% <0.00%> (ø)
...s/opentelemetry-propagator-ot-trace/src/version.ts	0.00% <0.00%> (ø)
packages/opentelemetry-host-metrics/src/version.ts	100.00% <100.00%> (ø)
...entelemetry-instrumentation-graphql/src/version.ts	100.00% <100.00%> (ø)
...de/opentelemetry-instrumentation-pg/src/version.ts	100.00% <100.00%> (ø)
...web/opentelemetry-plugin-react-load/src/version.ts	100.00% <100.00%> (ø)
... and 5 more

[vmarchaud]

Once again it seems we miss updating examples

This is a long standing issue for every release, we have few issues opened for adding examples in lerna so dependencies are bumped for each release. A part from that, we'll need to re-release a new version thats compatible with 1.0 of the API so i think updating manually examples can wait a little more.

[dyladan]

Not directly related to thi PR. Once again it seems we miss updating examples. e.g. express is still refering to 0.15.0.
Maybe we should simply remove them as there is no CI testing them nor is there someone having the time to keep them up and running. I guess it's quite a bad experience for users to start with non working examples.

These are generated automatically now. There's no way to really update the examples automatically since it likely requires code changes.