Cap ODEInterface to 0.4.8 to fix Julia 1.12+ solver loading

[ChrisRackauckas-Claude]

Problem

The tests / Core (julia 1) and tests / Core (julia pre) jobs fail on master with:

AssertionError: (dlSolversInfo[dlname]).error === nothing
caused by: UndefVarError(:ODEInterface_jll, ..., ODEInterface)

in ODEInterface/DLSolvers.jl (getAllMethodPtrs -> loadODESolvers), which errors Core/algorithm_tests.jl at the first solve(prob, dopri5(), ...). The Core (julia lts) / 1.10 job is unaffected and stays green.

Root cause

ODEInterface 0.5.0 (the only registered 0.5.x) has a Julia 1.12+ incompatibility. loadODESolvers() runs @eval ODEInterface begin using ODEInterface_jll end and then, in the same call frame, accesses the ODEInterface_jll global via getproperty. Under Julia 1.12's stricter binding-partition / world-age semantics, the binding created by using is only visible in a newer world age, so the in-frame access raises UndefVarError(:ODEInterface_jll). Every solver then records a load error and getAllMethodPtrs throws SolverODEnotLoaded. Julia 1.10 had more permissive binding visibility, so it stayed green.

This was reproduced locally on Julia 1.12.6 (a bare using ODEInterface; loadODESolvers() yields dopri5 error => UndefVarError(:ODEInterface_jll)).

Fix

The upstream fix (luchr/ODEInterface.jl#36, merged, tagged v0.5.1) switches to import ODEInterface_jll + @eval getproperty(...) and resolves it — but v0.5.1 is still not registered in General, so it cannot be selected via compat.

As the last working registered version, ODEInterface 0.4.8 uses the older local-gfortran build path (no ODEInterface_jll), which loads correctly on Julia 1.12/1.13. This PR caps ODEInterface = "0.4.8".

Follow-up: gfortran for the 0.4.8 source build

Capping to 0.4.8 reintroduces 0.4.8's behaviour of compiling the Fortran solvers from source in deps/build.jl. On a runner without gfortran that build hard-errors with Currently only gfortran is supported., which broke the tests / QA (julia lts) job (the julia 1 runner happened to have gfortran, lts did not). This PR therefore also passes apt-packages: "gfortran" to the grouped-tests.yml workflow, so every test job installs gfortran before building/testing. (When apt-packages is set the workflow runs on ubuntu-24.04 instead of ubuntu-latest, as intended.)

When ODEInterface 0.5.1 is registered, the cap can be relaxed back to 0.5 (>= 0.5.1), the jll-based path restored, and the apt-packages: gfortran line removed.

Verification (local)

• ODEInterface 0.4.8 + gfortran, Julia 1.10.11 lts (the failing QA job): ODEInterface resolves to 0.4.8, the gfortran-built solvers load, a dopri5() solve returns Success, and the QA suite passes (Aqua 7 pass + 1 pre-existing @test_broken, JET 1 pre-existing @test_broken).
• GROUP=Core Julia 1.12.6 (originally failing Core): all Core test files pass, Core/algorithm_tests.jl runs all solve calls without error.
• GROUP=Core Julia 1.10.11 lts: all Core test files pass — no regression.

Please ignore until reviewed by @ChrisRackauckas