Lua 5.3 STD string.pack incorrect signature

[checkraisefold]

The current signature for string.pack in the default Lua 5.3 STD is:

  string.pack:
    args:
      - type: string
    must_use: true

The correct signature, which is correct in the Luau STD, is:

  string.pack:
    args:
      - type: string
      - type: ...
    must_use: true

The same issue exists with string.unpack. This issue causes any usage of these functions that actually works to throw a selene warning, considering the function requires 2 arguments to work.

[checkraisefold]

The signature for assert is also incorrect. It always expects two arguments, despite it working fine with one.

[Kampfkarren]

assert is intentional, there are existing issue reports for that that I responded to.

[checkraisefold]

assert is intentional, there are existing issue reports for that that I responded to.

Reasoning for assert makes sense, but message with lint needs to be changed (already acknowledged). Made a quick PR to fix this issue.