Bring back POWER full builds

[nickva]

Try out the new VM

[nickva]

Adding the VM worked as expected, however it looks it's too slow to run tests.

For instance x64 tests times look like:

[2022-06-27T18:39:00.952Z]   couch_db: is_owner_test...ok
[2022-06-27T18:39:00.952Z]   module 'couch_db_tests'
[2022-06-27T18:39:00.952Z]     Database create/delete tests
[2022-06-27T18:39:01.301Z]       couch_db_tests:93: should_create_db...[0.015 s] ok
[2022-06-27T18:39:01.301Z]       couch_db_tests:102: should_delete_db...[0.013 s] ok
[2022-06-27T18:39:01.301Z]       [done in 0.034 s]
[2022-06-27T18:39:01.301Z]     Multiple database create/delete tests
[2022-06-27T18:39:01.651Z]       couch_db_tests:112: should_create_multiple_dbs...[0.063 s] ok
[2022-06-27T18:39:01.651Z]       couch_db_tests:125: should_delete_multiple_dbs...[0.069 s] ok
[2022-06-27T18:39:01.651Z]       [done in 0.138 s]
[2022-06-27T18:39:01.651Z]     Continious database create/delete tests
[2022-06-27T18:39:02.001Z]       couch_db_tests:138: should_create_delete_database_continuously (10 times)...[0.116 s] ok
[2022-06-27T18:39:03.209Z]       couch_db_tests:138: should_create_delete_database_continuously (100 times)...[1.107 s] ok

(From https://ci-couchdb.apache.org/blue/rest/organizations/jenkins/pipelines/jenkins-cm1/pipelines/FullPlatformMatrix/branches/jenkins-bring-back-ppc64le/runs/2/nodes/218/log/?start=0)

And PowerPC ones are quite a bit slower

[2022-06-27T18:50:16.187Z] couch_db: is_owner_test...ok
[2022-06-27T18:50:16.187Z] module 'couch_db_tests'
[2022-06-27T18:50:16.187Z]   Database create/delete tests
[2022-06-27T18:50:18.270Z]     couch_db_tests:93: should_create_db...[1.548 s] ok
[2022-06-27T18:50:19.869Z]     couch_db_tests:102: should_delete_db...[1.461 s] ok
[2022-06-27T18:50:19.869Z]     [done in 3.016 s]
[2022-06-27T18:50:19.869Z]   Multiple database create/delete tests
[2022-06-27T18:50:25.216Z]     couch_db_tests:112: should_create_multiple_dbs...*timed out*
[2022-06-27T18:50:25.216Z]     undefined
[2022-06-27T18:50:30.124Z]   couch_db_tests:125: should_delete_multiple_dbs...*timed out*
[2022-06-27T18:50:30.124Z]   undefined
[2022-06-27T18:50:30.602Z] [done in 10.003 s]
[2022-06-27T18:50:30.602Z] Continious database create/delete tests
[2022-06-27T18:50:48.560Z] couch_db_tests:138: should_create_delete_database_continuously (10 times)...[15.361 s] ok
[2022-06-27T18:52:01.403Z] couch_db_tests:138: should_create_delete_database_continuously (100 times)...[73.174 s] ok
[2022-06-27T18:52:01.403Z] [done in 88.542 s]
[2022-06-27T18:52:01.403Z] Database open tests

(From https://ci-couchdb.apache.org/blue/rest/organizations/jenkins/pipelines/jenkins-cm1/pipelines/FullPlatformMatrix/branches/jenkins-bring-back-ppc64le/runs/2/nodes/72/log/?start=0)

should_create_delete_database_continuously (100 times) is about 73x slower and should_create_db at 1.548 vs 0.015 s which also 100x slower.

It could be disk I/O or CPU throttling, haven't dove in to check yet, but I think will hold off enabling it for now as it would make the full build flaky.

[nickva]

A new VM was built with an NVMe disk which fixed the problem, so it looks good to go.

Eunit tests runs in 15 vs 12 on other nodes but interestingly, elixir and other tests run a bit faster, even.