Bump dotnet/sdk in /build/docker

Bumps dotnet/sdk from 9.0.305-azurelinux3.0 to 10.0.100-azurelinux3.0.

---
updated-dependencies:
- dependency-name: dotnet/sdk
  dependency-version: 10.0.100-azurelinux3.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

build/docker/Dockerfile

@@ -1,5 +1,5 @@
 # --platform tells docker to always use the host platform for the build not the target platform. Runtime container will use target platform.
-FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:9.0.305-azurelinux3.0 AS build
+FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:10.0.100-azurelinux3.0 AS build
 ARG TARGETARCH
 ARG FHIR_VERSION
 ARG ASSEMBLY_VER