[GITEA] Make atomic ssh keys replacement robust

- After stumbling upon golang/go#22397 and
reading the implementations I realized that Forgejo code doesn't have
`Sync()` and it doesn't properly error handle the `Close` function.
- (likely) Resolves https://codeberg.org/forgejo/forgejo/issues/1446

(cherry picked from commit 0efcb33)
(cherry picked from commit 04ef02c)
(cherry picked from commit 85f2065)
(cherry picked from commit 8d36b5c)
(cherry picked from commit 0f406dc)
(cherry picked from commit 347a2e7)

models/asymkey/ssh_key_authorized_keys.go

@@ -169,7 +169,12 @@ func RewriteAllPublicKeys(ctx context.Context) error {
 		return err
 	}
 
-	t.Close()
+	if err := t.Sync(); err != nil {
+		return err
+	}
+	if err := t.Close(); err != nil {
+		return err
+	}
 	return util.Rename(tmpPath, fPath)
 }
 

models/asymkey/ssh_key_authorized_principals.go

@@ -92,7 +92,12 @@ func RewriteAllPrincipalKeys(ctx context.Context) error {
 		return err
 	}
 
-	t.Close()
+	if err := t.Sync(); err != nil {
+		return err
+	}
+	if err := t.Close(); err != nil {
+		return err
+	}
 	return util.Rename(tmpPath, fPath)
 }