Update dependencies for krb5 external test

Dejagnu/TCL are no longer needed.  Installing kdcproxy enables krb5's
proxying tests, which exercise the krb5 TLS integration.

Signed-off-by: Robbie Harwood <rharwood@redhat.com>

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from #15850)

.github/workflows/ci.yml

@@ -224,7 +224,7 @@ jobs:
     - name: package installs
       run: |
         sudo apt-get update
-        sudo apt-get -yq install bison dejagnu gettext keyutils ldap-utils libldap2-dev libkeyutils-dev python3 python3-paste python3-pyrad slapd tcl-dev tcl-thread tcsh python3-virtualenv virtualenv
+        sudo apt-get -yq install bison gettext keyutils ldap-utils libldap2-dev libkeyutils-dev python3 python3-paste python3-pyrad slapd tcsh python3-virtualenv virtualenv python3-kdcproxy
     - name: install cpanm and Test2::V0 for gost_engine testing
       uses: perl-actions/install-with-cpanm@v1
       with: