fix: try npm 7

https://github.com/nextcloud/social/runs/7740827926?check_suite_focus=true
skjnldsv/read-package-engines-version-actions@v1.2 does not seem to like
the more flexible version specification.

package.json

@@ -62,7 +62,7 @@
 	],
 	"engines": {
 		"node": "^16.0.0",
-		"npm": "^7.0.0 | ^8.0.0"
+		"npm": "^7.0.0"
 	},
 	"devDependencies": {
 		"@babel/core": "^7.17.9",