Make the simple package index compatible with Artifactory:

[marcin-krystianc]

We found out that our current "package index" format is not compatible with Artifactory despite working just fine with pip.
I think the main reason was that links to the whl files were prefixed with ./.
I also added a sha256 to the whl files link as suggested in the https://peps.python.org/pep-0503.
I've confirmed that the new format works fine with Artifactory (I used a trial version in the cloud):

old version:

pip3 install --index-url https://[email protected]:cmVmdGtuOjAxOjE3NzIwMTAxODY6MWpZNTV6YmxPTldpNGRyaVZuUWRnWDFSNVlQ@trial564kcz.jfrog.io/artifactory/api/pypi/gr/simple confluent-kafka==2.6.1+gr
Looking in indexes: https://marcin.krystianc%40gmail.com:****@trial564kcz.jfrog.io/artifactory/api/pypi/gr/simple
Collecting confluent-kafka==2.6.1+gr
  ERROR: HTTP error 404 while getting https://trial564kcz.jfrog.io/artifactory/api/pypi/gr/simple/confluent-kafka/confluent_kafka-2.6.1%2Bgr-cp310-cp310-manylinux_2_28_x86_64.whl (from https://trial564kcz.jfrog.io/artifactory/api/pypi/gr/simple/confluent-kafka/)
ERROR: Could not install requirement confluent-kafka==2.6.1+gr from https://trial564kcz.jfrog.io/artifactory/api/pypi/gr/simple/confluent-kafka/confluent_kafka-2.6.1%2Bgr-cp310-cp310-manylinux_2_28_x86_64.whl because of HTTP error 404 Client Error:  for url: https://trial564kcz.jfrog.io/artifactory/api/pypi/gr/simple/confluent-kafka/confluent_kafka-2.6.1%2Bgr-cp310-cp310-manylinux_2_28_x86_64.whl for URL https://trial564kcz.jfrog.io/artifactory/api/pypi/gr/simple/confluent-kafka/confluent_kafka-2.6.1%2Bgr-cp310-cp310-manylinux_2_28_x86_64.whl (from https://trial564kcz.jfrog.io/artifactory/api/pypi/gr/simple/confluent-kafka/)

new version

pip3 install --index-url https://[email protected]:cmVmdGtuOjAxOjE3NzIwMDgzNTY6Q2pFc05UVWZRUzFiZnh1a2lwTE9XZlhPMkxv@trial564kcz.jfrog.io/artifactory/api/pypi/marcin2/simple confluent-kafka==2.6.1+gr
Looking in indexes: https://marcin.krystianc%40gmail.com:****@trial564kcz.jfrog.io/artifactory/api/pypi/marcin2/simple
Collecting confluent-kafka==2.6.1+gr
  Downloading https://trial564kcz.jfrog.io/artifactory/api/pypi/marcin2/packages/confluent-kafka/confluent_kafka-2.6.1%2Bgr-cp310-cp310-manylinux_2_28_x86_64.whl (3.8 MB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 3.8/3.8 MB 5.0 MB/s eta 0:00:00
Installing collected packages: confluent-kafka
  Attempting uninstall: confluent-kafka
    Found existing installation: confluent-kafka 2.6.0
    Uninstalling confluent-kafka-2.6.0:
      Successfully uninstalled confluent-kafka-2.6.0
Successfully installed confluent-kafka-2.6.1+gr