feat(ci)!: complete workflows revamp (#1437)

* chore(ci): move spec-file into scripts

* feat(ci)!: rework workflows and build processes

All Python setups route through one local action, and checks are much
more conditional. There is more to be done, but this is a significant
improvement in processing time and redundancy.

As well, nightly builds are made (though not made as GitHub releases..
yet).

* ci: remove symlinked CHANGELONG.md from build_docs.yml paths

* docs: update location of tagstudio.spec

* ci: enforce single quotes in github yaml files

* ci(tests): remove macOS pytest runner

---------

Co-authored-by: Travis Abendshien <46939827+CyanVoxel@users.noreply.github.com>

nix/package/pillow-jxl-plugin.nix

@@ -1,7 +1,6 @@
 # SPDX-FileCopyrightText: (c) TagStudio Contributors
 # SPDX-License-Identifier: GPL-3.0-only
 
-
 {
   buildPythonPackage,
   cmake,

nix/package/pyexiv2.nix

@@ -1,7 +1,6 @@
 # SPDX-FileCopyrightText: (c) TagStudio Contributors
 # SPDX-License-Identifier: GPL-3.0-only
 
-
 {
   autoPatchelfHook,
   buildPythonPackage,