Update Platform API URI

[pinin4fjords]

We get errors running in Seqera platform when using the old 'tower' API URI:

�[0;31mThe following invalid input values have been detected:
* --input: the file or directory 'https://api.cloud.seqera.io/workspaces/162690105070735/datasets/3IsL8QHGMIRMQFO1LDXLig/v/1/n/samplesheet_nf-aggregate.csv' does not exist.
�[0m
 -- Check script '.nextflow/assets/seqeralabs/nf-aggregate/./workflows/nf_aggregate/../../subworkflows/local/utils_nf_aggregate/../../nf-core/utils_nfvalidation_plugin/main.nf' at line: 55 or see 'nf-2atrw11Mi4s56h.log' file for more details

Switching to api.cloud.seqera.io makes things work.

[pinin4fjords]

Thanks @maxulysse !