(build) Be explicit about need for .NET 5

The current version of GitVersion.Tool that we are using requires .NET
5.x.  While this exists on some of the build images, it would appear
that it is being removed from others.

This commit explicitly adds the requirement as part of the build setup.

Once we upgrade to a newer version of GitVersion.Tool, we should add
again the explicit version that is required.

Author: gep13

.github/workflows/build.yml

@@ -29,6 +29,14 @@ jobs:
         sudo apt update
         sudo apt install -y mono-complete
         mono --version
+    - name: Install dotnet #needed for GitVersion
+      uses: actions/setup-dotnet@baa11fbfe1d6520db94683bd5c7a3818018e4309 # v5
+      with:
+        dotnet-version: |
+          5.0.x
+    - name: Report installed dotnet versions
+      run: |
+          dotnet --info
     - name: Build with Mono
       run: |
         chmod +x build.sh
@@ -56,6 +64,14 @@ jobs:
       with:
         path: tools
         key: ${{ runner.os }}-tools-${{ hashFiles('recipe.cake') }}
+    - name: Install dotnet #needed for GitVersion
+      uses: actions/setup-dotnet@baa11fbfe1d6520db94683bd5c7a3818018e4309 # v5
+      with:
+        dotnet-version: |
+          5.0.x
+    - name: Report installed dotnet versions
+      run: |
+          dotnet --info
     - name: Build with .Net Framework
       shell: powershell
       run: ./build.ps1 --verbosity=diagnostic --target=CI --testExecutionType=unit --shouldRunOpenCover=false --shouldBuildMsi=true
@@ -88,6 +104,14 @@ jobs:
       with:
         path: tools
         key: ${{ runner.os }}-tools-${{ hashFiles('recipe.cake') }}
+    - name: Install dotnet #needed for GitVersion
+      uses: actions/setup-dotnet@baa11fbfe1d6520db94683bd5c7a3818018e4309 # v5
+      with:
+        dotnet-version: |
+          5.0.x
+    - name: Report installed dotnet versions
+      run: |
+          dotnet --info
     - name: Build with Mono
       run: |
         export DOTNET_ROOT=$HOME/.dotnet

.github/workflows/test.yml

@@ -29,6 +29,14 @@ jobs:
         sudo apt update
         sudo apt install -y mono-complete
         mono --version
+    - name: Install dotnet #needed for GitVersion
+      uses: actions/setup-dotnet@baa11fbfe1d6520db94683bd5c7a3818018e4309 # v5
+      with:
+        dotnet-version: |
+          5.0.x
+    - name: Report installed dotnet versions
+      run: |
+          dotnet --info
     - name: Test with NUnit on Mono
       run: |
         chmod +x build.sh
@@ -55,6 +63,14 @@ jobs:
       with:
         path: tools
         key: ${{ runner.os }}-tools-${{ hashFiles('recipe.cake') }}
+    - name: Install dotnet #needed for GitVersion
+      uses: actions/setup-dotnet@baa11fbfe1d6520db94683bd5c7a3818018e4309 # v5
+      with:
+        dotnet-version: |
+          5.0.x
+    - name: Report installed dotnet versions
+      run: |
+          dotnet --info
     - name: Test with NUnit on .Net Framework
       run: .\build.bat  --verbosity=diagnostic --target=test --testExecutionType=all --shouldRunOpenCover=false
     - name: Upload Windows build results