Pin mcr.microsoft.com/dotnet/sdk Docker tag to 332e036 (#359)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.devcontainer/Dockerfile

@@ -1,5 +1,5 @@
 # Refer to https://hub.docker.com/_/microsoft-dotnet-sdk for available versions
-FROM mcr.microsoft.com/dotnet/sdk:9.0.202-noble
+FROM mcr.microsoft.com/dotnet/sdk:9.0.202-noble@sha256:332e0362dd210a10348d436a5fb7f87aeec28c2c53ac2c3c2659e57c22294d0e
 
 # Installing mono makes `dotnet test` work without errors even for net472.
 # But installing it takes a long time, so it's excluded by default.