v5: Add gen2 as allowed resources

[mathomp4]

This PR adds the ability to use gen2 resources:

https://circleci.com/docs/guides/execution-managed/using-docker/#docker-gen2-benefits

---

I did some tests with MAPL.

Assuming test-ci-2026Jun17 = Gen1 and feature/v2-tryout-gen2-try2 = Gen2, here’s the comparison. “Speedup” is Gen1 time / Gen2 time, so values above 1.00x mean Gen2 was faster.

Workflow / Job	Gen1 time	Gen2 time	Speedup	Time change
Workflow: build-GEOSldas	15:14	11:36	1.31x	23.9% faster
build-GEOSldas-on-ifort	6:55	7:57	0.87x	14.9% slower
build-GEOSldas-on-gfortran	15:13	11:35	1.31x	23.9% faster
Workflow: build-and-run-GEOSgcm	28:58	28:36	1.01x	1.3% faster
build-GEOSgcm-on-ifort	18:16	21:49	0.84x	19.4% slower
run-GCM-on-ifort	4:52	4:33	1.07x	6.5% faster
run-coupled-GCM-on-ifort	7:57	6:13	1.28x	21.8% faster
build-GEOSgcm-on-gfortran	25:16	25:33	0.99x	1.1% slower
run-GCM-on-gfortran	3:39	3:00	1.22x	17.8% faster
Workflow: build-and-test-MAPL	8:17	7:30	1.10x	9.5% faster
build-and-test-MAPL-as-Debug-on-ifort-using-Unix Makefiles	6:58	6:19	1.10x	9.3% faster
run-hello_world-Tutorial-with-ifort-built-with-Debug	1:07	1:08	0.99x	1.5% slower
run-parent_no_children-Tutorial-with-ifort-built-with-Debug	1:13	1:02	1.18x	15.1% faster
run-parent_one_child_import_via_extdata-Tutorial-with-ifort-built-with-Debug	1:07	0:59	1.14x	11.9% faster
run-parent_one_child_no_imports-Tutorial-with-ifort-built-with-Debug	1:09	0:55	1.25x	20.3% faster
run-parent_two_siblings_connect_import_export-Tutorial-with-ifort-built-with-Debug	1:04	0:58	1.10x	9.4% faster

Main takeaway: Gen2 helps some runtime/test jobs and the GEOSldas gfortran build a lot, but it is not uniformly faster for compilation. The big red flag is:

Job	Gen1	Gen2	Result
build-GEOSgcm-on-ifort	18:16	21:49	19.4% slower on Gen2
build-GEOSldas-on-ifort	6:55	7:57	14.9% slower on Gen2

So for your actual wall-clock workflows, the benefit looks like:

Workflow	Net benefit
build-GEOSldas	~24% faster
build-and-run-GEOSgcm	basically unchanged
build-and-test-MAPL	~9.5% faster

My read: Gen2 looks promising for the smaller MAPL tests and some run steps, but for GEOSgcm the critical path is still the gfortran build at ~25.5 minutes, so the whole workflow barely moves. For ifort-heavy build jobs, this one sample actually looks worse on Gen2.

[mathomp4]

Your development orb(s) have been published. It will expire in 30 days.
You can preview what this will look like on the CircleCI Orb Registry at the following link(s):
https://circleci.com/developer/orbs/orb/geos-esm/circleci-tools?version=dev:cf45abb3382826efc5fa25c957c9d17c8be141d6
https://circleci.com/developer/orbs/orb/geos-esm/circleci-tools?version=dev:alpha

[mathomp4]

Your development orb(s) have been published. It will expire in 30 days.
You can preview what this will look like on the CircleCI Orb Registry at the following link(s):
https://circleci.com/developer/orbs/orb/geos-esm/circleci-tools?version=dev:77ece7d541c6e07fab30913735cf9f0c90c8360b
https://circleci.com/developer/orbs/orb/geos-esm/circleci-tools?version=dev:alpha