Migrate Exasol provider to pyexasol 2.x

[joshuabvarghese]

This PR upgrades the Exasol provider to support pyexasol version 2.x.

• closes: Migrate exasol provider to pyexasol 2.x and remove the <2 cap #69123

As pyexasol 2.x introduces changes to the underlying library API, this PR includes the necessary refactoring of the Exasol hook, updates to the unit tests, and adjustments to the provider's dependencies and documentation to maintain full compatibility.

Key Changes:

• Variable Separation: Decoupled the Airflow Connection from ExaConnection in get_conn to resolve variable reuse typing errors.
• Runtime Validation: Added explicit type checks for query_params (enforcing a literal dict to match pyexasol's **query_params unpacking) and sql statements (rejecting lists in get_records/get_first). This respects the DbApiHook base class interface while failing fast on invalid inputs.
• Dependency Ceiling: Bumped pyproject.toml to pyexasol>=2.0.0,<3, establishing a proper major-version ceiling.
• Test Coverage: Added negative testing to verify the new runtime validations and fixed a mocked test that was previously hiding a runtime TypeError.
• Documentation: Updated README.rst, docs/index.rst, and docs/changelog.rst to reflect the breaking changes and new dependencies.

Testing

• mypy strictness verified locally (0 errors in exasol.py).
• Unit tests passing.
• Standalone runtime harness executed against installed pyexasol 2.2.2 to verify end-to-end type execution on conn.execute().

[github-actions]

uv.lock on main just moved via #69712 ("Support Paramiko 5 in SSH and SFTP providers"), commit 963d286 and this PR currently conflicts.

Quickest fix:

git fetch upstream main && git rebase upstream/main
rm uv.lock && uv lock
git add uv.lock && git rebase --continue
git push --force-with-lease

Automated nudge — ignore if you're not ready to rebase. This comment is updated in place on future uv.lock bumps.

[eladkal]

The list note stuff but nothing here strike as airflow breaking change is it?
Can you just remove the breaking changes title?

also, did you validate these statements? This feels AI generated. Please provide evidences that the points here are valid. Just referencing to the upstream docs/code should be enough

[baha-bouali]

There are two things I can confirm with the changelog

• with_column_names boolean fix: I can confirm that pyexasol's changelog has a dedicated bugfix (https://github.com/exasol/pyexasol/releases#release-2.2.1 - # 265)). So any value used to get forced to be True. Now it should require a real Boolean

• py.typed marker: Confirmed. In the Same Changelog batch above (# 298) pyexasol added it when swapping the deprecated rsa dependency for cryptography. I think that this is the actual mechanism not a breaking change.

However,

• get_records()/get_first() only accepting a single SQL string. I cannot confirm this one tho. No changelog says explicitly this changed in 2.x. However, it's consistent with every example in pyexasol's docs since they only show a single string. This means that's always the case.

• Parameters should be dict/Mapping: Can't confirm either, but no changelog ref to point to.

So, two claims are true, two are unverified assumptions.
I suggest to drop the "Breaking changes" title since it is not a change to the provider's own interface and drop the two unverifiable bullets entirely. Keep only the two we can back:

This provider now requires ``pyexasol>=2.0.0,<3``. pyexasol 2.0.0 added a
``py.typed`` marker and fixed ``export_params={"with_column_names": ...}``
to require a real boolean (previously any value, including ``False``, was
treated as ``True`` — pyexasol changelog, bugfix #265).