Fix node 20 issue on GHA CI

[Flamefire]

No description provided.

[joaquintides]

Hi @Flamefire, thanks for your contribution. Tests still fail for these jobs:

• https://github.com/boostorg/bimap/actions/runs/12215326386/job/34089119859?pr=47
• https://github.com/boostorg/bimap/actions/runs/12215326386/job/34089121257?pr=47
• https://github.com/boostorg/bimap/actions/runs/12215326386/job/34089121354?pr=47
• https://github.com/boostorg/bimap/actions/runs/12215326386/job/34089121505?pr=47

Any idea what's going on?

[Flamefire]

Some containers that don't need to be used. Reformatted to verify against the boost-ci template

[pdimov]

Why are you setting toolset to the wrong value (toolset: clang++-3.9 instead of toolset: clang-3.9), and then patching it back in the script?

[Flamefire]

Why are you setting toolset to the wrong value (toolset: clang++-3.9 instead of toolset: clang-3.9), and then patching it back in the script?

Not really required in this repo indeed. That was from a RegEx replacement to ensure the correct compiler is used. IIRC I temporarily used matrix.toolset as the compiler in the user config but then decided against it.
Changed