revert(3p/git): Revert merge of git upstream at v2.26.2

This causes cgit to serve error pages, which is undesirable.

This reverts commit 5229c9b232, reversing
changes made to f2b211131f.

third_party/git/hex.c

@@ -90,6 +90,11 @@ char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
 	return buffer;
 }
 
+char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
+{
+	return hash_to_hex_algop_r(buffer, sha1, &hash_algos[GIT_HASH_SHA1]);
+}
+
 char *oid_to_hex_r(char *buffer, const struct object_id *oid)
 {
 	return hash_to_hex_algop_r(buffer, oid->hash, the_hash_algo);
@@ -103,6 +108,11 @@ char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *a
 	return hash_to_hex_algop_r(hexbuffer[bufno], hash, algop);
 }
 
+char *sha1_to_hex(const unsigned char *sha1)
+{
+	return hash_to_hex_algop(sha1, &hash_algos[GIT_HASH_SHA1]);
+}
+
 char *hash_to_hex(const unsigned char *hash)
 {
 	return hash_to_hex_algop(hash, the_hash_algo);