Do not run Oracle GraalVM benchmarks on manually scheduled GH Actions

[Akirathan]

Engine benchmarks GH Action and Standard library benchmarks GH Action both have two jobs - one that runs benchmarks on GraalVM CE and other one that runs on Oracle GraalVM. The jobs run sequentially, that is how GH Actions work. This is OK for daily benchmark runs, but not for benchmarks that are manually scheduled. When manually scheduling, GraalVM CE benchmarks are sufficient.

Let's add another option along with dry-run benchmarks option:

that will be something like "Run only on GraalVM CE".

The changes should be done somewhere along these lines:
https://github.com/enso-org/enso/blob/develop/.github/workflows/engine-benchmark.yml#L13

[Akirathan]

Fixed by #10829 that removed Oracle GraalVM benchmarks both from daily jobs, and from jobs scheduled manually.