feat: update nuget plugin to support net4 target framework

Author: dkontorovskyy

package.json

@@ -77,7 +77,7 @@
     "snyk-module": "1.9.1",
     "snyk-mvn-plugin": "2.4.0",
     "snyk-nodejs-lockfile-parser": "1.16.0",
-    "snyk-nuget-plugin": "1.12.0",
+    "snyk-nuget-plugin": "1.12.1",
     "snyk-php-plugin": "1.6.4",
     "snyk-policy": "1.13.5",
     "snyk-python-plugin": "^1.13.0",