chore: 0.20.0 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.

note from maintainers: this skips 0.17, 0.18, and 0.19 in order to bring version parity with API and core.

[vmarchaud]

dont you need to cherry-pick examples again ?

[dyladan]

After looking at them more closely, they can't be simply released as-is. I am going to update examples in a follow-up but it doesn't need to block the release.

[codecov]

Codecov Report

Merging #520 (24d66a0) into main (26d9c43) will decrease coverage by 0.05%.
The diff coverage is 40.00%.

@@            Coverage Diff             @@
##             main     #520      +/-   ##
==========================================
- Coverage   94.86%   94.81%   -0.06%     
==========================================
  Files         143      150       +7     
  Lines        8860     9153     +293     
  Branches      868      904      +36     
==========================================
+ Hits         8405     8678     +273     
- Misses        455      475      +20     

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 7 more