chore: remove ic-ref from the binary cache

[ericswanson-dfinity]

Description

Since we removed dfx start --emulator, we don't need to bundle ic-ref anymore.

How Has This Been Tested?

CI and

$ dfx-wip cache install
  Version v0.15.3+rev3.dirty-4399f83e installed successfully.
$ ls $(dfx-wip cache show)
base				ic-admin			ic-nns-init			mo-doc				replica
canister_sandbox		ic-btc-adapter			ic-starter			mo-ide				sandbox_launcher
dfx				ic-https-outcalls-adapter	icx-proxy			moc				sns

Checklist:

• The title of this PR complies with Conventional Commits.
• I have edited the CHANGELOG accordingly.