updated modules' dockerfile tags

modules/cms-kit/database/Dockerfile

@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/core/sdk:3.0-buster AS build
+FROM mcr.microsoft.com/dotnet/core/sdk:7.0-buster AS build
 COPY . .
 
 WORKDIR /templates/service/host/IdentityServerHost

modules/cms-kit/host/Volo.CmsKit.HttpApi.Host/Dockerfile

@@ -1,8 +1,8 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:3.0-buster-slim AS base
+FROM mcr.microsoft.com/dotnet/core/aspnet:7.0-buster-slim AS base
 WORKDIR /app
 EXPOSE 80
 
-FROM mcr.microsoft.com/dotnet/core/sdk:3.0-buster AS build
+FROM mcr.microsoft.com/dotnet/core/sdk:7.0-buster AS build
 WORKDIR /src
 COPY . .
 WORKDIR /src/templates/service/host/Volo.CmsKit.HttpApi.Host

modules/cms-kit/host/Volo.CmsKit.IdentityServer/Dockerfile

@@ -1,8 +1,8 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:3.0-buster-slim AS base
+FROM mcr.microsoft.com/dotnet/core/aspnet:7.0-buster-slim AS base
 WORKDIR /app
 EXPOSE 80
 
-FROM mcr.microsoft.com/dotnet/core/sdk:3.0-buster AS build
+FROM mcr.microsoft.com/dotnet/core/sdk:7.0-buster AS build
 WORKDIR /src
 COPY . .
 WORKDIR /src/templates/service/host/Volo.CmsKit.IdentityServer

modules/docs/app/VoloDocs.Migrator/Dockerfile

@@ -1,8 +1,8 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:3.0-buster-slim AS base
+FROM mcr.microsoft.com/dotnet/core/aspnet:7.0-buster-slim AS base
 WORKDIR /app
 EXPOSE 80
 
-FROM mcr.microsoft.com/dotnet/core/sdk:3.0-buster AS build
+FROM mcr.microsoft.com/dotnet/core/sdk:7.0-buster AS build
 WORKDIR /src
 COPY . .
 WORKDIR "/src/modules/docs/app/VoloDocs.Migrator"

modules/docs/app/VoloDocs.Web/Dockerfile

@@ -1,8 +1,8 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:3.0-buster-slim AS base
+FROM mcr.microsoft.com/dotnet/core/aspnet:7.0-buster-slim AS base
 WORKDIR /app
 EXPOSE 80
 
-FROM mcr.microsoft.com/dotnet/core/sdk:3.0-buster AS build
+FROM mcr.microsoft.com/dotnet/core/sdk:7.0-buster AS build
 WORKDIR /src
 COPY . .
 WORKDIR "/src/modules/docs/app/VoloDocs.Web"