Pin macos-15 build runner

[jamescrosswell]

Resolves #3752

#skip-changelog

[bitsandfoxes]

The ever changing flow of pin/unpin...

[jamescrosswell]

We're getting this error on the macos-15 runner:

Error: /Users/runner/.dotnet/packs/Microsoft.Android.Sdk.Darwin/34.0.145/targets/Microsoft.Android.Sdk.Tooling.targets(31,5): error XA5205: Cannot find `aapt`. Please install the Android SDK Build-Tools package with the `/Users/runner/Library/Android/sdk/tools/android` program. [/Users/runner/work/sentry-dotnet/sentry-dotnet/samples/Sentry.Samples.Maui/Sentry.Samples.Maui.csproj::TargetFramework=net8.0-android]

Looks like that runner doesn't (yet) include the android build tools. Workaround described here:
actions/runner-images#10814 (comment)

      # https://github.com/actions/runner-images/issues/10814
      - name: Workaround build-tools issue
        run: | 
          curl https://dl.google.com/android/repository/build-tools_r35_macosx.zip > $ANDROID_HOME/build-tools_r35_macosx.zip
          cd $ANDROID_HOME
          mkdir build-tools
          unzip build-tools_r35_macosx.zip
          mv android-15 build-tools/35.0.0

[jamescrosswell]

Now getting an error about mono (when running the tests on macos):

System.IO.FileNotFoundException: Could not find 'mono' host. Make sure that 'mono' is installed on the machine and is available in PATH environment variable.

[bruno-garcia]

[+] Ensure System.Reflection.Metadata is not missing

Is this a integration test flake @vaind?

I actually don't understand the failure

[jamescrosswell]

Is this a integration test flake @vaind?

It's not the reason the integration test failed... that was because of this:

    /Users/runner/.dotnet/packs/Microsoft.Android.Sdk.Darwin/34.0.145/tools/Xamarin.Android.Tooling.targets(100,5): error XA5207: Could not find android.jar for API level 34. This means the Android SDK platform for API level 34 is not installed; it was expected to be in `/Users/runner/Library/Android/sdk/platforms/android-34/android.jar`. [/maui-app/maui-app.csproj::TargetFramework=net8.0-android]
    /Users/runner/.dotnet/packs/Microsoft.Android.Sdk.Darwin/34.0.145/tools/Xamarin.Android.Tooling.targets(100,5): error XA5207: You can install the missing API level by running `dotnet build -t:InstallAndroidDependencies -f net8.0-android "-p:AndroidSdkDirectory=/Users/runner/Library/Android/sdk"`, or change the project to target an API version that is installed. [/maui-app/maui-app.csproj::TargetFramework=net8.0-android]

The Android SDKs obviously aren't included on the macos-15 runner, so we need to install these ourselves. I already added that for the build step:

sentry-dotnet/.github/workflows/build.yml

Lines 126 to 130 in e6e6424

	- name: Install Android SDKs
	if: runner.os == 'macOS'
	run: |
	dotnet build src/Sentry/Sentry.csproj -t:InstallAndroidDependencies -f:net7.0-android -p:AcceptAndroidSDKLicenses=True -p:AndroidSdkPath="/usr/local/lib/android/sdk/"
	dotnet build src/Sentry/Sentry.csproj -t:InstallAndroidDependencies -f:net8.0-android -p:AcceptAndroidSDKLicenses=True -p:AndroidSdkPath="/usr/local/lib/android/sdk/"

With any luck, this does the same for the integration tests:

sentry-dotnet/integration-test/cli.Tests.ps1

Lines 145 to 152 in 40b9757

	if (Test-Path env:CI)
	{
	dotnet build $name/$name.csproj -t:InstallAndroidDependencies -f:$framework-android -p:AcceptAndroidSDKLicenses=True -p:AndroidSdkPath="/usr/local/lib/android/sdk/" | ForEach-Object { Write-Host $_ }
	if ($LASTEXITCODE -ne 0)
	{
	throw "Failed to install android dependencies."
	}
	}

It's kind of painful to work through all these issues since they only happen on CI... and now we're getting to the last ones (in the integration tests) there's a minimum 60-90 minute wait after each change to see if it worked.