ci(mcp): Pin mcp package to <2.0.0 while alphas are in flight

[ericapisani]

The mcp package is currently releasing 2.0 alpha versions. Pin the test suite to <2.0.0 to avoid picking up unstable pre-releases until the stable 2.0 release expected at the end of July 2026.

[github-actions]

Codecov Results 📊

✅ 90151 passed | ⏭️ 6305 skipped | Total: 96456 | Pass Rate: 93.46% | Execution Time: 311m 11s

📊 Comparison with Base Branch

Metric	Change
Total Tests	—
Passed Tests	📈 +29
Failed Tests	📉 -29
Skipped Tests	—

✨ No test changes detected

All tests are passing successfully.

✅ Patch coverage is 100.00%. Project has 2399 uncovered lines.
❌ Project coverage is 89.92%. Comparing base (base) to head (head).

Coverage diff

@@            Coverage Diff             @@
##          main       #PR       +/-##
==========================================
- Coverage    89.95%    89.92%    -0.03%
==========================================
  Files          192       192         —
  Lines        23809     23809         —
  Branches      8218      8218         —
==========================================
+ Hits         21418     21410        -8
- Misses        2391      2399        +8
- Partials      1337      1338        +1

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Generated by Codecov Action

[sentry]

Bug: The include: "<2.0.0" specifier for mcp will not prevent testing against pre-release versions like 2.0.0a1 due to PEP 440 version comparison rules.
_{Severity: MEDIUM}

Suggested Fix

To correctly exclude specific pre-release versions, use inequality specifiers. For example, change the include value to something like "!=2.0.0a1,!=2.0.0a2" to explicitly filter out known alpha versions, similar to how the starlite integration is configured.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: scripts/populate_tox/config.py#L306

Potential issue: The configuration change for the `mcp` integration uses `"include":
"<2.0.0"` with the intent to skip testing against `2.0.0-alpha` versions. However, this
will not work as expected. According to PEP 440, a pre-release version like `2.0.0a1` is
considered less than `2.0.0`. Since the `SpecifierSet` in `_prefilter_releases` is
created with `prereleases=True`, `2.0.0a1` will pass the `include_versions` filter. The
script will then identify it as the latest pre-release and may select it for testing,
which is contrary to the stated goal of the change.

_{Did we get this right? 👍 / 👎 to inform future reviews.}