Clear DID cache for did:plc: after identity.updateHandle

On a self-hosted PDS, updating an account's handle via
`com.atproto.identity.updateHandle` won't change the reported `handle`
value in `com.atproto.repo.describeRepo`, since the did cache still has
stale data.

To solve this, we just clear the cache after the updateHandle endpoint
gets hit.

packages/pds/src/api/com/atproto/identity/updateHandle.ts

@@ -1,11 +1,11 @@
-import assert from 'node:assert'
-import { InvalidRequestError } from '@atproto/xrpc-server'
 import { DAY, MINUTE } from '@atproto/common'
+import { InvalidRequestError } from '@atproto/xrpc-server'
+import assert from 'node:assert'
+import AppContext from '../../../../context'
 import { normalizeAndValidateHandle } from '../../../../handle'
 import { Server } from '../../../../lexicon'
-import AppContext from '../../../../context'
-import { httpLogger } from '../../../../logger'
 import { ids } from '../../../../lexicon/lexicons'
+import { httpLogger } from '../../../../logger'
 
 export default function (server: Server, ctx: AppContext) {
   server.com.atproto.identity.updateHandle({
@@ -80,6 +80,8 @@ export default function (server: Server, ctx: AppContext) {
         }
       }
 
+      await ctx.didCache.clearEntry(account.did)
+
       try {
         await ctx.sequencer.sequenceHandleUpdate(requester, handle)
         await ctx.sequencer.sequenceIdentityEvt(requester, handle)