all: Remove unused method receivers (#8462)

Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>

cmd/stcrashreceiver/stcrashreceiver.go

@@ -59,7 +59,7 @@ func (r *crashReceiver) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 }
 
 // serveGet responds to GET requests by serving the uncompressed report.
-func (r *crashReceiver) serveGet(fullPath string, w http.ResponseWriter, _ *http.Request) {
+func (*crashReceiver) serveGet(fullPath string, w http.ResponseWriter, _ *http.Request) {
 	fd, err := os.Open(fullPath)
 	if err != nil {
 		http.Error(w, "Not found", http.StatusNotFound)
@@ -77,7 +77,7 @@ func (r *crashReceiver) serveGet(fullPath string, w http.ResponseWriter, _ *http
 
 // serveHead responds to HEAD requests by checking if the named report
 // already exists in the system.
-func (r *crashReceiver) serveHead(fullPath string, w http.ResponseWriter, _ *http.Request) {
+func (*crashReceiver) serveHead(fullPath string, w http.ResponseWriter, _ *http.Request) {
 	if _, err := os.Lstat(fullPath); err != nil {
 		http.Error(w, "Not found", http.StatusNotFound)
 	}
@@ -136,6 +136,6 @@ func (r *crashReceiver) servePut(reportID, fullPath string, w http.ResponseWrite
 }
 
 // 01234567890abcdef... => 01/23
-func (r *crashReceiver) dirFor(base string) string {
+func (*crashReceiver) dirFor(base string) string {
 	return filepath.Join(base[0:2], base[2:4])
 }