Night job scripts

[LesnyRumcajs]

Summary of changes
Changes introduced in this pull request:

• nightly checks scripts to be installed on a nightly runner with instructions

Reference issue to close (if applicable)

Closes #1455

Other information and links

For the moment latest snapshots are not downloaded nor used as Forest won't work with v15. I put a snapshot from February on the server. After we introduce support for v15 we can re-iterate on that. #1476

[codecov]

Codecov Report

Merging #1475 (a64c392) into main (7783ef8) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1475      +/-   ##
==========================================
- Coverage   44.19%   44.19%   -0.01%     
==========================================
  Files         322      322              
  Lines       28483    28483              
==========================================
- Hits        12589    12588       -1     
- Misses      15894    15895       +1     

Impacted Files	Coverage Δ
vm/actor/src/builtin/miner/mod.rs	33.49% <0.00%> (-0.05%)	⬇️

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