chore: remove unused utils (#852)

`utils.js` exported `idToKey` and `parseVersion`, neither of which are
used anywhere. This removes them.

src/utils.js

@@ -1,23 +1,10 @@
-import b4a from 'b4a'
 import sodium from 'sodium-universal'
 import { keyToPublicId } from '@mapeo/crypto'
 import { createHash } from 'node:crypto'
 import stableStringify from 'json-stable-stringify'
 
 const PROJECT_INVITE_ID_SALT = Buffer.from('mapeo project invite id', 'ascii')
 
-/**
- * @param {String|Buffer} id
- * @returns {Buffer | Uint8Array}
- */
-export function idToKey(id) {
-  if (b4a.isBuffer(id)) {
-    return /** @type {Buffer} */ (id)
-  }
-
-  return b4a.from(/** @type {String} */ (id), 'hex')
-}
-
 /**
  *
  * @param {Buffer|String} key
@@ -31,18 +18,6 @@ export function keyToId(key) {
   return key.toString('hex')
 }
 
-/**
- * @param {String} version
- * @returns {{coreId: String, blockIndex: Number}}
- */
-export function parseVersion(version) {
-  const [coreId, blockIndex] = version.split('@')
-  return {
-    coreId,
-    blockIndex: Number(blockIndex),
-  }
-}
-
 export class ExhaustivenessError extends Error {
   /** @param {never} value */
   constructor(value) {