V15: Fix docker (#17722)

* Bump dotnet version

* Ensure LF line endings for shell scripts

.gitattributes

@@ -46,6 +46,7 @@
 *.xml text=auto
 *.resx text=auto
 *.yml text eol=lf core.whitespace whitespace=tab-in-indent,trailing-space,tabwidth=2
+*.sh eol=lf
 
 *.csproj text=auto merge=union
 *.vbproj text=auto merge=union

templates/UmbracoProject/Dockerfile

@@ -1,10 +1,10 @@
-FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS base
+FROM mcr.microsoft.com/dotnet/aspnet:9.0 AS base
 USER $APP_UID
 WORKDIR /app
 EXPOSE 8080
 EXPOSE 8081
 
-FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
+FROM mcr.microsoft.com/dotnet/sdk:9.0 AS build
 ARG BUILD_CONFIGURATION=Release
 WORKDIR /src
 COPY ["UmbracoProject/UmbracoProject.csproj", "UmbracoProject/"]