packit: allow SHA-1 signatures when tests are run

The "PrivKey class : resign cert" test fails on Fedora because SHA-1
signatures are deprecated there:
https://fedoraproject.org/wiki/SHA1SignaturesGuidance. Since it's
Fedora-specific and the test failure is useful in terms of detecting it
and deciding how to address it in programs that use scapy in
environments like that it should be enough to allow SHA-1 signatures on
Packit only.

Closes #4794

Author: evverx

.packit.yml

@@ -17,7 +17,7 @@ actions:
     - "git clone https://src.fedoraproject.org/rpms/scapy .packit_rpm --depth=1"
     # Drop the "sources" file so rebase-helper doesn't think we're a dist-git
     - "rm -fv .packit_rpm/sources"
-    - "sed -i '/^# check$/a%check\\nOPENSSL_CONF=$(python3 ./.config/ci/openssl.py) ./test/run_tests -c test/configs/linux.utsc -K ci_only -K scanner' .packit_rpm/scapy.spec"
+    - "sed -i '/^# check$/a%check\\nOPENSSL_ENABLE_SHA1_SIGNATURES=1 OPENSSL_CONF=$(python3 ./.config/ci/openssl.py) ./test/run_tests -c test/configs/linux.utsc -K ci_only -K scanner' .packit_rpm/scapy.spec"
     - "sed -i '/^BuildArch/aBuildRequires: can-utils' .packit_rpm/scapy.spec"
     - "sed -i '/^BuildArch/aBuildRequires: libpcap' .packit_rpm/scapy.spec"
     - "sed -i '/^BuildArch/aBuildRequires: openssl' .packit_rpm/scapy.spec"