ci: upgrade dotnet version from 3 to 8

This primarily fixes the issue where "no usable version of libssl was found" (see [this post](https://stackoverflow.com/a/72836925)) as newer Ubuntu versions upgraded OpenSSL to version 3.0, which are not supported by dotnet versions 5 and older. Therefore, we can upgrade the local version of dotnet to one that does support this version of OpenSSL. This has the added benefit of using a more up-to-date LTS version of dotnet as v3.1 reached EOL at the end of 2022.

Author: sherwinski

.github/workflows/nuget_deploy.yml

@@ -11,14 +11,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Install SSL dependencies
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y libssl-dev
       - name: Setup dotnet
         uses: actions/setup-dotnet@v1
         with:
-          dotnet-version: 3.1.x
+          dotnet-version: 8.x
       - name: Build and Pack
         run: |
           dotnet restore