chore: release v6.0.0 for Node.js 24 support

- Update to Node.js 24 runtime (runs.using: node24)
- Bump version to 6.0.0
- Update README with v6 release notes
- Rebuild dist

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "upload-artifact",
-  "version": "5.0.0",
+  "version": "6.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "upload-artifact",
-      "version": "5.0.0",
+      "version": "6.0.0",
       "license": "MIT",
       "dependencies": {
         "@actions/artifact": "^5.0.0",
@@ -419,6 +419,7 @@
       "integrity": "sha512-e7jT4DxYvIDLk1ZHmU/m/mB19rex9sv0c2ftBtjSBv+kVM/902eh0fINUzD7UwLLNR+jU585GxUJ8/EBfAM5fw==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@babel/code-frame": "^7.27.1",
         "@babel/generator": "^7.28.5",