chore(deps): update dependency koa-session to v6.4.0 (#24)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package.json

@@ -4,9 +4,9 @@
     "version": "1.0.0",
     "devDependencies": {
         "@types/koa-bodyparser": "4.3.10",
-        "@types/koa-session": "5.10.6",
+        "@types/koa-session": "6.4.5",
         "extend2": "1.0.1",
-        "koa-session": "6.2.0",
+        "koa-session": "6.4.0",
         "uuid": "9.0.0",
         "egg-multipart": "2.13.1",
         "egg-view": "2.1.3",