build(deps-dev): bump yjs from 13.6.20 to 13.6.21

Bumps [yjs](https://github.com/yjs/yjs) from 13.6.20 to 13.6.21.
- [Release notes](https://github.com/yjs/yjs/releases)
- [Commits](yjs/yjs@v13.6.20...v13.6.21)

---
updated-dependencies:
- dependency-name: yjs
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

packages/tldraw/package.json

@@ -83,6 +83,6 @@
     "vite-plugin-css-injected-by-js": "^3.5.2",
     "y-presence": "^0.2.3",
     "y-websocket": "^2.1.0",
-    "yjs": "^13.6.20"
+    "yjs": "^13.6.21"
   }
 }

packages/wisemapping/package.json

@@ -80,6 +80,6 @@
     "vite": "^6.0.7",
     "y-presence": "^0.2.3",
     "y-websocket": "^2.1.0",
-    "yjs": "^13.6.20"
+    "yjs": "^13.6.21"
   }
 }

yarn.lock

@@ -1576,7 +1576,7 @@ __metadata:
     vite-plugin-css-injected-by-js: "npm:^3.5.2"
     y-presence: "npm:^0.2.3"
     y-websocket: "npm:^2.1.0"
-    yjs: "npm:^13.6.20"
+    yjs: "npm:^13.6.21"
   languageName: unknown
   linkType: soft
 
@@ -1701,7 +1701,7 @@ __metadata:
     vite: "npm:^6.0.7"
     y-presence: "npm:^0.2.3"
     y-websocket: "npm:^2.1.0"
-    yjs: "npm:^13.6.20"
+    yjs: "npm:^13.6.21"
   languageName: unknown
   linkType: soft
 
@@ -12006,12 +12006,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"yjs@npm:^13.6.20":
-  version: 13.6.20
-  resolution: "yjs@npm:13.6.20"
+"yjs@npm:^13.6.21":
+  version: 13.6.21
+  resolution: "yjs@npm:13.6.21"
   dependencies:
     lib0: "npm:^0.2.98"
-  checksum: 10/7c64494f8bff24a95e237ed0e0c561efb9e8d451655620f04963dbbe5910b60e8ea978a0048fa377477493cbacbf002220f39445cf2ede298dc9a0f20ed5b942
+  checksum: 10/5c13655e5bca9aee9d9cd1a383a85e3f4998d08f43ee1b658c83b88637ea18d77e6aae32ee41869e90e643465ead203035770b950cdcff7ddfce1c0a0dab2f2d
   languageName: node
   linkType: hard