opentelemetry-exporter-otlp-common: add shared package for common OTLP utilities

[herin049]

Description

This PR adds a new opentelemetry-exporter-otlp-common package to provide common utilities for OTLP Protobuf/JSON/gRPC exporters.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

uv run tox -e py314-test-opentelemetry-exporter-otlpcommon-latest

Does This PR Require a Contrib Repo Change?

• Yes. - Link to PR:
• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[github-actions]

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[Copilot]

Pull request overview

This PR introduces a new opentelemetry-exporter-otlp-common package intended to centralize shared OTLP exporter utilities (notably OTLP/HTTP retry/compression logic and metrics aggregation/temporality helpers), and wires it into the monorepo build/test/CI configuration.

Changes:

• Added the new opentelemetry-exporter-otlp-common distribution with internal OTLP/HTTP client + aggregation utilities and accompanying tests.
• Integrated the new package into workspace membership, packaging lists, tox envs, and GitHub Actions test/lint jobs.
• Added pinned test requirement sets (oldest/latest) for the new package and updated the changelog entry.

Reviewed changes

Copilot reviewed 19 out of 21 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
uv.lock	Adds the new package as a workspace member and records dependency lock updates.
tox.ini	Adds test/lint envs and dependency mappings for the new package.
pyproject.toml	Includes/excludes the new package paths for repo-level tooling.
eachdist.ini	Adds the new distribution to per-dist packaging configuration.
.github/workflows/test.yml	Adds CI test jobs for the new package across Python versions/platforms.
.github/workflows/lint.yml	Adds CI lint job for the new package.
.changelog/5252.added	Documents the addition of the new shared OTLP utilities package.
exporter/opentelemetry-exporter-otlp-common/pyproject.toml	Defines the new distribution metadata, deps, and build configuration.
exporter/opentelemetry-exporter-otlp-common/README.rst	Documents installation and basic usage for the new OTLP/HTTP utilities.
exporter/opentelemetry-exporter-otlp-common/LICENSE	Adds the Apache 2.0 license text for the new package directory.
exporter/opentelemetry-exporter-otlp-common/src/.../_http.py	Implements OTLPHTTPClient (compression + retry/backoff + transport integration).
exporter/opentelemetry-exporter-otlp-common/src/.../_aggregation.py	Implements env-driven metrics temporality + histogram aggregation selection helpers.
exporter/opentelemetry-exporter-otlp-common/src/.../__init__.py	Initializes the new package module.
exporter/opentelemetry-exporter-otlp-common/src/.../version/__init__.py	Introduces version metadata for the new distribution.
exporter/opentelemetry-exporter-otlp-common/src/.../py.typed	Marks the package as typed for type checkers.
exporter/opentelemetry-exporter-otlp-common/tests/test_http_client.py	Adds unit tests for retry, timeout, compression, and shutdown behaviors.
exporter/opentelemetry-exporter-otlp-common/tests/test_aggregation.py	Adds unit tests for env-driven temporality/aggregation selection.
exporter/opentelemetry-exporter-otlp-common/tests/__init__.py	Test package marker for the new package.
exporter/opentelemetry-exporter-otlp-common/test-requirements.in	Defines test dependency inputs for the new package.
exporter/opentelemetry-exporter-otlp-common/test-requirements.oldest.txt	Pinned “oldest” resolved test dependency set for CI/tox.
exporter/opentelemetry-exporter-otlp-common/test-requirements.latest.txt	Pinned “latest” resolved test dependency set for CI/tox.

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[DylanRussell]

I don't like having oldest/latest really.. I feel like it's a lot of boilerplate and some maintenance toil for not much benefit..

[herin049]

I agree that it's inconvenient to work with but I do think it is valuable in catching compatibility issues in your package. For example, unintentionally relying on a new feature/functionality added in a new minor version of a package. Also, given that these files are generated via uv pip compile I think that tools like Renovate are able to automatically regenerate these.