fix(x509): mark dirNameTag as constructed in parseNameConstraintsExtension

[MichaelWaters001]

Issue:
Fails to parse the dirName from a valid cert with a name constraint.

Testing:
created a valid cert with openssl v3.5.2
config something like this

nameConstraints = critical, \
    excluded;DNS:bad.example.com, \
    excluded;email:bad@example.com, \
    excluded;URI:.bad.example.com, \
    excluded;IP:192.168.1.0/255.255.255.255, \
    excluded;dirName:excluded_dn

[ excluded_dn ]
C=US
O=AllowedOrg

gen the cert
openssl req -x509 -new -key ca.key -days 365 -out ca.crt -config openssl_ca.cnf -extensions v3_ca

Parse the resulting cert text with excrypto inspecting the structure.
Parsing this cert previously hit the default unhandled case, this fix adjusts the case to 0xA4 and now properly parses the dirName.