fix(ci): snapshot parity test: fetch param files on init and drop CI cache

[hanabi1224]

Summary of changes

The cache step does not work properly on buildjet build agents and is causing timeout in lotus

https://github.com/ChainSafe/forest/actions/runs/9029022947/job/24810699319#step:2:42

/usr/bin/tar: ../../../../../var: Cannot mkdir: Permission denied
/usr/bin/tar: ../../../../../var/tmp/filecoin-proof-parameters: Cannot mkdir: No such file or directory

Changes introduced in this pull request:

• drop CI cache
• run forest-tool fetch-params --keys in docker-compose init service

Reference issue to close (if applicable)

Closes

Other information and links

Change checklist

• [x] I have performed a self-review of my own code,
• [x] I have made corresponding changes to the documentation,
• [x] I have added tests that prove my fix is effective or that my feature works (if possible),
• [x] I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

[LesnyRumcajs]

Should we simplify RPC checks job as well?

[hanabi1224]

Should we simplify RPC checks job as well?

@LesnyRumcajs Done.

[LesnyRumcajs]

Should we also get rid of the cache for the devnet checks?

[hanabi1224]

Should we also get rid of the cache for the devnet checks?

@LesnyRumcajs I'd prefer experimenting with the devnet change in a separate PR. The 2k param files are large (>2GB), dropping the CI cache might make it much slower. It also requires a bigger change in the docker-compose file