feat: mark packages as side-effect free

Author: AriPerkkio

packages/istanbul-lib-coverage/package.json

@@ -23,6 +23,7 @@
     "dist"
   ],
   "type": "module",
+  "sideEffects": false,
   "types": "./dist/index.d.mts",
   "exports": "./dist/index.mjs",
   "publishConfig": {

packages/istanbul-lib-instrument/package.json

@@ -24,6 +24,7 @@
     "dist"
   ],
   "type": "module",
+  "sideEffects": false,
   "types": "./dist/index.d.mts",
   "exports": "./dist/index.mjs",
   "publishConfig": {

packages/istanbul-lib-report/package.json

@@ -25,6 +25,7 @@
     "dist"
   ],
   "type": "module",
+  "sideEffects": false,
   "types": "./dist/index.d.mts",
   "exports": "./dist/index.mjs",
   "publishConfig": {

packages/istanbul-lib-source-maps/package.json

@@ -25,6 +25,7 @@
     "dist"
   ],
   "type": "module",
+  "sideEffects": false,
   "types": "./dist/index.d.mts",
   "exports": "./dist/index.mjs",
   "publishConfig": {