Add AllocCheck allocation tests and CI job

[ChrisRackauckas-Claude]

Summary

• Add AllocCheck to test dependencies for allocation testing
• Add test/alloc_tests.jl with example allocation-free surrogate implementation tests
• Add alloccheck CI job in Tests.yml running with GROUP=nopre

Context

SurrogatesBase.jl is an interface package that defines abstract types (AbstractDeterministicSurrogate, AbstractStochasticSurrogate) and function stubs (update!, parameters, etc.). Since there are no concrete implementations to optimize, this PR adds allocation testing infrastructure that:

1. Serves as an example for downstream packages implementing surrogates
2. Demonstrates how to write allocation-free surrogate operations
3. Uses @check_allocs from AllocCheck.jl to verify zero allocations

The allocation tests run in a separate "nopre" group to avoid interference with precompilation.

Test plan

• All existing tests pass
• New allocation tests pass with GROUP=nopre
• CI AllocCheck job runs successfully

cc @ChrisRackauckas

🤖 Generated with Claude Code

[ChrisRackauckas-Claude]

CI Status

The pre (Julia 1.13 prerelease) tests are failing, but this is a pre-existing issue - JET.jl doesn't yet support Julia 1.13:

JET [c3a54625] log:
├─possible versions are: 0.0.1 - 0.11.3 or uninstalled
├─restricted to versions 0.9 - 0.11 by project
└─restricted by julia compatibility requirements to versions: uninstalled — no versions left

All tests pass on:

• Julia 1 (stable) - Ubuntu, Windows ✅
• Julia LTS - Ubuntu, Windows ✅
• AllocCheck job ✅

The macOS jobs are still pending but should also pass.

cc @ChrisRackauckas