chore: 2.0.0/0.16.0 release proposal

[aabmass]

Draft release notes https://github.com/GoogleCloudPlatform/opentelemetry-operations-js/releases/edit/untagged-5b5a347c344230601362

Note the major version bump since we dropped support for some older nodeJS versions in #477. Discussion is in that issue.

[codecov]

Codecov Report

Merging #521 (48560f0) into main (81916f2) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #521   +/-   ##
=======================================
  Coverage   95.99%   95.99%           
=======================================
  Files          18       18           
  Lines         649      649           
  Branches      118      118           
=======================================
  Hits          623      623           
  Misses         26       26           

Impacted Files	Coverage Δ
...telemetry-cloud-monitoring-exporter/src/version.ts	100.00% <100.00%> (ø)
.../opentelemetry-cloud-trace-exporter/src/version.ts	100.00% <100.00%> (ø)

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