ci: retire the smoke workflow now that the real pipeline is green

smoke.yml was scaffolding to prove the self-hosted runners could execute
anything at all, back when checkout and the SDK were still unresolved. ci.yml
now builds, gates and releases on both runners, so the smoke jobs only
duplicate its environment checks. Leaving dead workflows around is exactly the
debt that confuses the next reader.

This commit also serves as the pipeline's first real push-triggered run: every
green run so far was a workflow_dispatch.

.gitea/workflows/smoke.yml

@@ -1,35 +0,0 @@
-# Gitea Actions smoke test for the self-hosted runners.
-# Deliberately uses NO `uses:` steps: Gitea resolves actions from
-# data.forgejo.org, which does not carry actions/checkout@v6 or
-# actions/setup-dotnet@v4, so the .github workflows cannot run here as-is.
-# Checkout is therefore done with plain git against the same instance.
-name: smoke
-on:
-  workflow_dispatch:
-
-jobs:
-  windows-smoke:
-    runs-on: windows-latest
-    steps:
-      - name: Environment
-        shell: pwsh
-        run: |
-          Write-Host "host=$env:COMPUTERNAME user=$env:USERNAME cores=$env:NUMBER_OF_PROCESSORS"
-          dotnet --list-sdks
-          git --version
-
-  linux-build:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Environment
-        run: |
-          echo "host=$(hostname) user=$(whoami) cores=$(nproc)"
-          dotnet --list-sdks
-          git --version
-      - name: Clone and build a real project
-        run: |
-          set -e
-          rm -rf src-smoke
-          git clone --depth 1 https://git.snakedesert.se/erik/acdream.git src-smoke
-          cd src-smoke
-          dotnet build src/AcDream.Launcher.Core/AcDream.Launcher.Core.csproj -c Release --nologo