[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 0f406dc4d2a440b6109f07223f387bd11e2e7e80)
(cherry picked from commit 347a2e7372583aa63e54dc906091437b45ecdb72)
(cherry picked from commit f6c04d6b8626c1c500f773e10e9839469149f285)
(cherry picked from commit cf8b64f937)

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)
 }