Claude/fix macos publish mono 3 ps kw (#11)

* Replace mono/nuget.exe with dotnet nuget commands

Modern macOS runners (macos-15, macos-14) no longer have mono pre-installed,
causing publish actions to fail. This change replaces all mono-based NuGet
commands with native dotnet CLI equivalents:

- Replaced 'mono .config/nuget.exe sources add' with 'dotnet nuget add source'
- Replaced 'mono .config/nuget.exe setApiKey' with 'dotnet nuget update source'
- Moved dotnet installation step before NuGet credential setup to ensure
  dotnet is available when needed

The dotnet CLI NuGet commands are cross-platform and don't require mono,
resolving the macOS x64 publish failure while maintaining functionality
across all platforms (macOS, Linux, Windows).

* Install mono via brew for vcpkg NuGet binary caching

vcpkg internally requires mono to execute nuget.exe for NuGet binary
caching operations on macOS/Linux, even when NuGet sources are configured
via dotnet CLI. Since vcpkg hasn't yet implemented support for using
dotnet nuget directly, we need to install mono.

Changes:
- Added 'brew install mono' step to all macOS workflow jobs
- Reverted NuGet credential setup to use 'mono .config/nuget.exe'
- Reverted buildnative.sh to use mono for setting NuGet API keys
- Moved dotnet installation to after the build step (only needed for
  dotnet tool restore, paket restore, and running tests)

This resolves the "Could not fetch mono" error from vcpkg while
maintaining functionality across all platforms.

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: krauthaufen

.github/workflows/publish.yml

@@ -13,10 +13,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
-      - name: Install Dotnet
-        uses: actions/setup-dotnet@v4
-        with:
-          global-json-file: global.json
+      - name: Install Mono
+        run: brew install mono
       - name: 'Setup NuGet Credentials'
         shell: 'bash'
         run: >
@@ -35,6 +33,10 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: ./buildnative.sh x86_64
+      - name: Install Dotnet
+        uses: actions/setup-dotnet@v4
+        with:
+          global-json-file: global.json
       - name: Restore Tools
         run: dotnet tool restore
       - name: Restore
@@ -52,10 +54,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
-      - name: Install Dotnet
-        uses: actions/setup-dotnet@v4
-        with:
-          global-json-file: global.json
+      - name: Install Mono
+        run: brew install mono
       - name: 'Setup NuGet Credentials'
         shell: 'bash'
         run: >
@@ -166,10 +166,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
-      - name: Install Dotnet
-        uses: actions/setup-dotnet@v4
-        with:
-          global-json-file: global.json
+      - name: Install Mono
+        run: brew install mono
       - name: 'Setup NuGet Credentials'
         shell: 'bash'
         run: >
@@ -205,10 +203,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
-      - name: Install Dotnet
-        uses: actions/setup-dotnet@v4
-        with:
-          global-json-file: global.json
+      - name: Install Mono
+        run: brew install mono
       - name: 'Setup NuGet Credentials'
         shell: 'bash'
         run: >