funding: github/sponsors/audiojs (field + FUNDING.yml); patch bump (release sweep)

Author: dy

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: audiojs

package.json

@@ -1,6 +1,6 @@
 {
   "name": "digital-filter",
-  "version": "2.4.1",
+  "version": "2.4.2",
   "type": "module",
   "sideEffects": false,
   "description": "Digital filter design & processing: IIR, FIR, smoothing, adaptive, multirate",
@@ -69,5 +69,6 @@
   },
   "devDependencies": {
     "tst": "^9.4.0"
-  }
+  },
+  "funding": "https://github.com/sponsors/audiojs"
 }