go: re-do the entire thing

This is a mega-change, but attempting to split this up further is
probably not worth the effort.

Summary:

1. Bump up bazel, rules_go, and others.
2. Switch to new go target naming (bye bye go_default_library)
3. Move go deps to go.mod/go.sum, use make gazelle generate from that
4. Bump up Python deps a bit

And also whatever was required to actually get things to work - loads of
small useless changes.

Tested to work on NixOS and Ubuntu 20.04:

   $ bazel build //...
   $ bazel test //...

Change-Id: I8364bdaa1406b9ae4d0385a6b607f3e7989f98a9
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1583
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/tools/gostatic/tarify/BUILD.bazel b/tools/gostatic/tarify/BUILD.bazel
index 7bc841b..9a6dab5 100644
--- a/tools/gostatic/tarify/BUILD.bazel
+++ b/tools/gostatic/tarify/BUILD.bazel
@@ -1,15 +1,15 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
 
 go_library(
-    name = "go_default_library",
+    name = "tarify_lib",
     srcs = ["main.go"],
     importpath = "code.hackerspace.pl/hscloud/tools/gostatic/tarify",
     visibility = ["//visibility:private"],
-    deps = ["@com_github_golang_glog//:go_default_library"],
+    deps = ["@com_github_golang_glog//:glog"],
 )
 
 go_binary(
     name = "tarify",
-    embed = [":go_default_library"],
+    embed = [":tarify_lib"],
     visibility = ["//visibility:public"],
 )