Bump dotnet/sdk from 8.0.401-jammy to 8.0.401-1-jammy in /Backend

Bumps dotnet/sdk from 8.0.401-jammy to 8.0.401-1-jammy.

---
updated-dependencies:
- dependency-name: dotnet/sdk
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Backend/Dockerfile

@@ -7,7 +7,7 @@
 ############################################################
 
 # Docker multi-stage build
-FROM mcr.microsoft.com/dotnet/sdk:8.0.401-jammy AS builder
+FROM mcr.microsoft.com/dotnet/sdk:8.0.401-1-jammy AS builder
 WORKDIR /app
 
 # Copy csproj and restore (fetch dependencies) as distinct layers.