fix(handlers): tighten tar header pattern

Numeric fields are stored as padded octal numbers, not decimals.

unblob/handlers/archive/tar.py

@@ -214,10 +214,10 @@ class TarUnixHandler(_TarHandler):
             r""
             #  (pattern would be too big)   char name[100]
             + _padded_field(r"[0-7]", 8)  # char mode[8]
-            + _padded_field(r"[0-9]", 8)  # char uid[8]
-            + _padded_field(r"[0-9]", 8)  # char gid[8]
-            + _padded_field(r"[0-9]", 12)  # char size[12]
-            + _padded_field(r"[0-9]", 12)  # char mtime[12]
+            + _padded_field(r"[0-7]", 8)  # char uid[8]
+            + _padded_field(r"[0-7]", 8)  # char gid[8]
+            + _padded_field(r"[0-7]", 12)  # char size[12]
+            + _padded_field(r"[0-7]", 12)  # char mtime[12]
             + _padded_field(r"[0-7]", 8)  # char chksum[8]
             + r"[0-7\x00]"  # char typeflag[1] - no extensions
             # Extending/dropping typeflag pattern would cover all tar formats,