chore: update CODEOWNERS (#19)

## Description

Make the accounts-team the code owners of this monorepo (so this would
reduce the gh code owner notifications temporarily). We are actively
reworking this repo for now, but we might want to revert/update the code
owners in the future.

.github/CODEOWNERS

@@ -1,13 +1,4 @@
 # Lines starting with '#' are comments.
 # Each line is a file pattern followed by one or more owners.
 
-*                                    @MetaMask/engineering
-
-/packages/keyring-api                @MetaMask/accounts-engineers
-
-/packages/keyring-snap               @MetaMask/accounts-engineers
-
-/packages/keyring-eth-hd             @MetaMask/accounts-engineers
-/packages/keyring-eth-ledger-bridge  @MetaMask/devs
-/packages/keyring-eth-simple         @MetaMask/accounts-engineers
-/packages/keyring-eth-trezor         @MetaMask/accounts-engineers
+*                                    @MetaMask/accounts-engineers