Add `crates.io-infra` repository under automation (private)

[Kobzol]

Repo: https://github.com/rust-lang/crates.io-infra

This is a private repository. I'm not sure if it should be archived or not, the linked website doesn't seem to work.

CC @pietroalbini

Extracted from GH:

org = "rust-lang"
name = "crates.io-infra"
description = "is ur crates.io running?"
bots = []

[access.teams]
infra = "pull"
crates-io-on-call = "write"
crates-io = "write"
security = "pull"

[access.individuals]
badboy = "admin"
hi-rustin = "write"
mdtro = "write"
JohnTitor = "write"
rust-lang-owner = "admin"
carols10cents = "write"
Mark-Simulacrum = "admin"
Xylakant = "write"
rylev = "admin"
tshepang = "write"
justahero = "write"
jtgeibel = "write"
Turbo87 = "write"
skade = "write"
LawnGnome = "write"
listochkin = "write"
jdno = "admin"
pietroalbini = "admin"