ci: drop loader validation step, keep JSON syntax check only

The loader step shells out to go get github.com/pdat-cz/pda-fieldbus,
which doesn't resolve (canonical home is git.pda.cz). This repo has no
Go code; loader-level validation is documented as a local workflow in
the README via pda-fieldbus poll --dry-run.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -12,49 +12,9 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: actions/setup-go@v5
-        with:
-          go-version: "1.25"
-          cache: false
-
       - name: JSON syntax check
         run: |
           for f in profiles/*.json; do
             echo "checking $f"
             python3 -m json.tool "$f" > /dev/null
           done
-
-      - name: Schema validation via pda-fieldbus loader
-        working-directory: ${{ runner.temp }}
-        run: |
-          mkdir -p validator && cd validator
-          go mod init validator
-          go get github.com/pdat-cz/pda-fieldbus@latest
-          cat > main.go <<'EOF'
-          package main
-
-          import (
-              "fmt"
-              "os"
-
-              "github.com/pdat-cz/pda-fieldbus/pkg/proto/profile"
-          )
-
-          func main() {
-              if len(os.Args) != 2 {
-                  fmt.Fprintln(os.Stderr, "usage: validator <profiles-dir>")
-                  os.Exit(2)
-              }
-              m, err := profile.LoadDirs(os.Args[1])
-              if err != nil {
-                  fmt.Fprintln(os.Stderr, "FAIL:", err)
-                  os.Exit(1)
-              }
-              for n, p := range m {
-                  fmt.Printf("OK %s  device=%s/%s  points=%d  derived=%d\n",
-                      n, p.Device.Manufacturer, p.Device.Model,
-                      len(p.Points), len(p.Derived))
-              }
-          }
-          EOF
-          go run . "$GITHUB_WORKSPACE/profiles"