build: modernize with "go fix -stringscut": use strings.Cut

backend/chunker/chunker_internal_test.go

@@ -43,7 +43,7 @@ func testPutLarge(t *testing.T, f *Fs, kilobytes int) {
 type settings map[string]any
 
 func deriveFs(ctx context.Context, t *testing.T, f fs.Fs, path string, opts settings) fs.Fs {
-	fsName := strings.Split(f.Name(), "{")[0] // strip off hash
+	fsName, _, _ := strings.Cut(f.Name(), "{") // strip off hash
 	configMap := configmap.Simple{}
 	for key, val := range opts {
 		configMap[key] = fmt.Sprintf("%v", val)

backend/ftp/ftp_internal_test.go

@@ -43,7 +43,7 @@ func TestCommandEncodingNeutralisesCRLF(t *testing.T) {
 type settings map[string]any
 
 func deriveFs(ctx context.Context, t *testing.T, f fs.Fs, opts settings) fs.Fs {
-	fsName := strings.Split(f.Name(), "{")[0] // strip off hash
+	fsName, _, _ := strings.Cut(f.Name(), "{") // strip off hash
 	configMap := configmap.Simple{}
 	for key, val := range opts {
 		configMap[key] = fmt.Sprintf("%v", val)

backend/http/http.go

@@ -543,7 +543,7 @@ func (f *Fs) readDir(ctx context.Context, dir string) (names []string, err error
 		return nil, fmt.Errorf("failed to readDir: %w", err)
 	}
 
-	contentType := strings.SplitN(res.Header.Get("Content-Type"), ";", 2)[0]
+	contentType, _, _ := strings.Cut(res.Header.Get("Content-Type"), ";")
 	switch contentType {
 	case "text/html":
 		names, err = parse(u, res.Body)