[GITEA] Make atomic ssh keys replacement robust

- After stumbling upon https://github.com/golang/go/issues/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 0efcb334c2f123d0869a30d684189eb31e8b983f)
(cherry picked from commit 04ef02c0dd98c7437acb39383d311c0901366508)
(cherry picked from commit 85f2065c9bc6ded9c21909ec76a9e8fc2d22f462)
(cherry picked from commit 8d36b5cce66864e190bad3c9b0973e37ca774a22)
(cherry picked from commit 378dc30fb5a88ffe185c54de7e69224289038bff)
(cherry picked from commit 2b28bf826e51b8ccb4a693001c03ffe6132f7842)
(cherry picked from commit d0625a001e5f8fe202865bec7aadcf0c551d556d)
(cherry picked from commit f161a4f60f1cde80a41bece4929836257b9e0423)
(cherry picked from commit 7430ca43e57683ca324fb20269a60e05cb393589)
(cherry picked from commit ab6d38daf7eeb1dc993bfc0ac1a326af65128168)
(cherry picked from commit 0f703fd02e69bdcf2f77e120ff8641f1b8089020)
(cherry picked from commit 6931a8f6bbfa0fe4f68b462f88c4a3db7ea06306)
(cherry picked from commit 5e2065c1c0ac66d90fae23f989077fa8cb0416ef)
(cherry picked from commit 38c812acfffe4c83099881a8b47489caba64b42a)
(cherry picked from commit 494874e23f2edb90beabe0827dadefa035e35a71)
(cherry picked from commit d396b7fd47c20d08844f8de1255a32fe0de25249)
(cherry picked from commit 7babc6efe11d0950ac47d3d4724bb5d414bdd6aa)
(cherry picked from commit 2d4dbbe7418d6c1a3a47c7e65350cf65fc9dca19)

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)
 }