fix: avoid using rm -rf for a regular file

If dnsreport.sqlite3 isn't regular, then there's something deeply
unexpected with the file system and we wouldn't want to zap something
that may be precious to the user.

internal/cmd/gardener/internal/dnsreport/dnsreport.go

@@ -67,7 +67,7 @@ func (s *Subcommand) Main(ctx context.Context) {
 
 	// if the database is not good, truncate it and restart
 	if !isGood {
-		log.Infof("rm -rf %s", s.Database)
+		log.Infof("rm -f %s", s.Database)
 		_ = os.Remove(s.Database)
 	}
 

internal/cmd/gardener/internal/sync/sync.go

@@ -44,7 +44,7 @@ func (s *Subcommand) Main() {
 	// TODO(bassosimone): an alternative would be to somehow take note of the fact
 	// that the database needs merging from an updated repository, but doing that
 	// would require us to write a more complex diff.
-	runtimex.Try0(shellx.Run(log.Log, "rm", "-rf", s.DNSReportDatabase))
+	runtimex.Try0(shellx.Run(log.Log, "rm", "-f", s.DNSReportDatabase))
 
 	// clone a new working copy
 	runtimex.Try0(shellx.Run(log.Log, "git", "clone", testListsRepo, s.RepositoryDir))

internal/cmd/gardener/internal/sync/sync_test.go

@@ -85,7 +85,7 @@ func TestWorkingAsIntended(t *testing.T) {
 	// expectations for commands
 	expect := []string{
 		fmt.Sprintf("rm -rf %s", repodir),
-		fmt.Sprintf("rm -rf %s", dnsreportfile),
+		fmt.Sprintf("rm -f %s", dnsreportfile),
 		fmt.Sprintf("git clone https://github.com/citizenlab/test-lists %s", repodir),
 		fmt.Sprintf("cd %s", repodir),
 		"git checkout -b gardener_20230315T114300Z",