IGNITE-26785 Change release version for ignite-3.1.0 branch (#6818)

Author: zstan

gradle.properties

@@ -30,7 +30,7 @@ org.gradle.jvmargs=-Xmx4g -Dfile.encoding=UTF-8
 
 # Project version to assign to the java projects and native platform builds.
 # After modifying this version run `./gradlew :platforms:updateVersion` to update files needed for C/C++, .NET and Python builds.
-projectVersion = 3.1.0-SNAPSHOT
+projectVersion = 3.1.0
 
 # Versions to use to build DB API Driver wheels.
 dbapiPythonVersions = 39,310,311,312,313

modules/platforms/dotnet/version.json

@@ -1,6 +1,6 @@
 {
     "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/main/src/NerdBank.GitVersioning/version.schema.json",
-    "version": "3.1.0-snapshot",
+    "version": "3.1.0",
     "publicReleaseRefSpec": [
         "^refs/heads/main",
         "^refs/heads/ignite-3\\.\\d+.*$"