Bump version to 1.32.0-unstable (#8099)

Author: brbrr

src/Nethermind/Directory.Build.props

@@ -15,7 +15,7 @@
     <Copyright>Demerzel Solutions Limited</Copyright>
     <Product>Nethermind</Product>
     <SourceRevisionId Condition="'$(Commit)' != ''">$(Commit)</SourceRevisionId>
-    <VersionPrefix>1.31.0</VersionPrefix>
+    <VersionPrefix>1.32.0</VersionPrefix>
     <VersionSuffix>unstable</VersionSuffix>
   </PropertyGroup>