Set version to '2.6'

Author: AArnott

version.json

@@ -1,8 +1,8 @@
 {
-  "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/master/src/NerdBank.GitVersioning/version.schema.json",
-  "version": "2.6-rc.2",
-  "nugetPackageVersion": {
-    "semVer": 2
+  "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/main/src/NerdBank.GitVersioning/version.schema.json",
+  "version": "2.6",
+  "nuGetPackageVersion": {
+    "semVer": 2.0
   },
   "publicReleaseRefSpec": [
     "^refs/heads/main$",
@@ -11,4 +11,4 @@
   "cloudBuild": {
     "setVersionVariables": false
   }
-}
+}