Add GitHub workflow to build and publish the NuGet package

.gitattributes

@@ -0,0 +1 @@
+*.sh text eol=lf

.github/workflows/publish.yml

@@ -0,0 +1,33 @@
+name: Publish NuGet
+
+# Run manually to build the package with the version in Python.Runtime.csproj and push it to nuget.org
+on: workflow_dispatch
+
+jobs:
+  publish:
+    # Only publish what is merged, a pushed version can't be replaced
+    if: github.ref == 'refs/heads/master'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write # lets NuGet/login exchange the GitHub OIDC token for a short-lived nuget.org API key
+    steps:
+      - uses: actions/checkout@v7
+        with:
+          persist-credentials: false
+
+      - uses: actions/setup-dotnet@v6
+        with:
+          dotnet-version: 10.0.x
+
+      # The temporary API key expires after 1 hour, plenty for the build below
+      - name: NuGet login
+        id: login
+        uses: NuGet/login@v1
+        with:
+          user: ${{ secrets.NUGET_USER }}
+
+      - name: Build and push
+        env:
+          NUGET_API_KEY: ${{ steps.login.outputs.NUGET_API_KEY }}
+        run: ./build_push_nuget.sh

build_push_nuget.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# Builds Python.Runtime, packs the QuantConnect.pythonnet NuGet and symbol packages into ./artifacts
+# with the <Version> in Python.Runtime.csproj and pushes them to nuget.org when NUGET_API_KEY is set
+#
+# Requires git and the .NET 10 SDK.
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT="$ROOT/src/runtime/Python.Runtime.csproj"
+OUTPUT="$ROOT/artifacts"
+
+# Everything under pythonnet/ is packed as content, so drop stale build outputs and __pycache__ first
+git -C "$ROOT" clean -fdXq -- pythonnet
+
+echo "Packing NuGet package"
+rm -rf "$OUTPUT"
+dotnet pack "$PROJECT" --configuration Release --output "$OUTPUT"
+
+ls "$OUTPUT"
+
+if [[ -n "${NUGET_API_KEY:-}" ]]; then
+    echo "Pushing to nuget.org"
+    # Also pushes the .snupkg symbol package next to it
+    dotnet nuget push "$OUTPUT"/*.nupkg --api-key "$NUGET_API_KEY" --source https://api.nuget.org/v3/index.json
+fi

src/runtime/Python.Runtime.csproj

@@ -35,7 +35,7 @@
         <PackagePath>contentFiles/any/any/</PackagePath>
         <PackageCopyToOutput>true</PackageCopyToOutput>
       </TfmSpecificPackageFile>
-      <TfmSpecificPackageFile Include="../../pythonnet/**">
+      <TfmSpecificPackageFile Include="../../pythonnet/**" Exclude="../../pythonnet/**/.*">
         <PackagePath>contentFiles/any/any/pythonnet</PackagePath>
         <PackageCopyToOutput>true</PackageCopyToOutput>
       </TfmSpecificPackageFile>