Qiskit / qiskit-ibm-runtime / 30573130508

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Improve QPY version mismatch error when deserializing jobs (#3002)

Peek the QPY header before `qpy.load` and raise a clear `QiskitError`
when the embedded Qiskit version is newer than the installed one. Fixes
#2426.

When job data includes circuits serialized with a newer Qiskit than the
client has installed, users used to get a vague warning from
`qiskit.qpy.load` about a "provided QPY file." This PR checks the QPY
header in `RuntimeDecoder` first and fails with a short message that
names both versions and suggests `pip install -U qiskit`.

###Changes

- Add `_validate_qpy_qiskit_version` / `_load_qpy` in `json.py`; use
them for `QuantumCircuit` and `Instruction` decoding.
- Release note: `release-notes/unreleased/2426.bug.rst`
- Tests: `TestQpyQiskitVersionValidation` (newer version → clear error;
matching version still decodes)
- Did not change when `job.inputs` loads data, `service.job()` already
skips params, so this covers the paths that actually call `qpy.load`.

Fixes #2426

### AI/LLM disclosure

- [x] I didn't use LLM tooling, or only used it privately.
- [ ] I used the following tool to help write this PR description:
- [ ] I used the following tool to generate or modify code:

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