[CI]: Let a patch or minor release edit only __about__.py #877

Found while reviewing PR #876: release SDK 3.0.1.

Problem

RELEASING.md says a release bumps __version__ in __about__.py. A core release must also edit five other files, or CI fails:

• packages/aws-durable-execution-sdk-python-conformance-tests{,-otel,-telemetry}/pyproject.toml pin aws-durable-execution-sdk-python==3.0.1.
• .github/tests/otel_lifecycle_compatibility_test.py and .github/tests/otel_legacy_registration_rejection_test.py assert that the installed core version is 3.0.1.

PR #738: release SDK 2.0.1 needed the same pin edits. The conformance packages also pin otel ==2.0.0 and telemetry-exporter ==1.0.0. The lifecycle test also asserts otel 2.0.0. So otel and telemetry-exporter releases have the same problem.

Why the exact versions add nothing

Conformance pins:

1. The root hatch default, test and types environments install every packages/* member from the checkout.
2. So an exact pin resolves only when it equals the checkout's version.
3. The conformance Lambda bundles do not read the pin. Core conformance copies the SDK source into lambda-build/. OTel and telemetry conformance install the SDK from git at the commit under test.
4. The conformance packages are not published.
5. So the pin never selects a version. It can only fail to resolve after a bump.

Test assertions:

1. Both tests run after .github/scripts/install_otel_test_wheels.py.
2. That script installs the wheel whose version matches __about__.py. It then checks the installed files against that wheel.
3. So the installed version always equals __about__.py. The assertions fail only when someone forgets to edit them.

Proposed change

• The conformance packages use ranges, as the otel and telemetry-exporter packages already do: aws-durable-execution-sdk-python>=3.0.0,<4, aws-durable-execution-sdk-python-otel>=2.0.0,<3, aws-durable-execution-sdk-python-telemetry-exporter>=1.0.0,<2.
• The two tests check the major version, for example Version(version("aws-durable-execution-sdk-python")).major == 3. The lifecycle test checks otel major 2 the same way.
• The legacy test keeps otel == "1.0.0", because that environment installs that exact release from PyPI.

A major release still edits the ranges and the major checks.

Acceptance criteria

• With only the core __about__.py set to 3.0.2, hatch run test:all, hatch run test-wheel-otel:test and hatch run test-wheel-otel-legacy:test pass. The wheel lanes need hatch build in the core and otel package directories first.
• The same commands pass with only the otel __about__.py set to 2.0.1, and with only the telemetry-exporter __about__.py set to 1.0.1.