script/packagecloud: remove EOL distros

Remove distros which have reached end of life, and remove some
commented-out entries for versions which have already been listed
elsewhere.  Promptly trimming EOL versions makes our releases faster
since we need not upload packages for those versions.

Note that we remove CentOS 5 because we're no longer building packages
for it.  Since RHEL is not freely available, we must rely on building
packages for CentOS, which means we must use CentOS's EOL dates, not
RHEL's.

script/packagecloud.rb

@@ -27,31 +27,22 @@
 # https://packagecloud.io/docs#os_distro_version
 $distro_name_map = {
   # RHEL EOL https://access.redhat.com/support/policy/updates/errata
-  "centos/5" => [
-    "el/5" # End of Extended Support November 30, 2020
-  ],
   "centos/6" => [
     "el/6", # End of Extended Support June 30, 2024
     "scientific/6",
   ],
   "centos/7" => [
     "el/7",
     "scientific/7",
-    #"el/8", # BOL ~2019-2020?
     # Fedora EOL check https://fedoraproject.org/wiki/End_of_life
     # or https://en.wikipedia.org/wiki/Fedora_version_history#Version_history
-    "fedora/28", # EOL ~Oct 2019
     "fedora/29", # EOL ~2020
     "fedora/30", # EOL ~2020
-    # "fedora/30", # BOL ~May 2019
     # opensuse https://en.opensuse.org/Lifetime
     # or https://en.wikipedia.org/wiki/OpenSUSE_version_history
-    "opensuse/42.3", # EOL 2019-06-30
-    "opensuse/15.0", # EOL 2019-11-25
     "opensuse/15.1", # EOL 2020-11
     # SLES EOL https://www.suse.com/lifecycle/
     "sles/11.4", # LTSS ends 31 Mar 2022
-    "sles/12.0", # LTSS ends 01 July 2019
     "sles/12.1", # LTSS ends 31 May 2020
     "sles/12.2", # LTSS ends 31 Mar 2021
     "sles/12.3", # LTSS ends 30 Jun 2022
@@ -66,13 +57,7 @@
   # Mint EOL https://linuxmint.com/download_all.php
   "debian/8" => [
     "debian/jessie",     # EOL June 30, 2020
-    "linuxmint/qiana",   # EOL April 2019
-    "linuxmint/rafaela", # EOL April 2019
-    "linuxmint/rebecca", # EOL April 2019
-    "linuxmint/rosa",    # EOL April 2019
     "ubuntu/trusty",     # ESM April 2022
-    "ubuntu/vivid",      # EOL February 4, 2016
-    "ubuntu/wily"        # EOL July 28, 2016
   ],
   "debian/9" => [
     "debian/stretch",   # EOL June 2022
@@ -85,11 +70,7 @@
     "linuxmint/tina",   # EOL April 2023
     "linuxmint/tricia", # EOL April 2023
     "ubuntu/xenial",    # ESM April 2024
-    "ubuntu/yakkety",   # EOL July 20, 2017
-    "ubuntu/zesty",     # EOL January 13, 2018
-    "ubuntu/artful",    # EOL July 19 2018
     "ubuntu/bionic",    # ESM April 2028
-    "ubuntu/cosmic",    # EOL July 2019
     "ubuntu/disco",     # EOL April 2020
   ],
   "debian/10" => [