github: modernize and format CI file

.editorconfig

@@ -13,5 +13,8 @@ trim_trailing_whitespace = true
 [Makefile]
 indent_style = tab
 
+[*.yml]
+indent_size = 2
+
 [*.tex]
 max_line_length = 100

.github/workflows/build.yml

@@ -1,48 +1,61 @@
 name: "Build"
 on:
-    pull_request:
-    push:
+  pull_request:
+  push:
+  merge_group:
+
 jobs:
-    # uses nix
-    nix_build:
-        runs-on: ubuntu-latest
-        steps:
-            -   uses: actions/checkout@v2.3.4
-            -   uses: cachix/install-nix-action@v17
-            -   run: nix-build
-            #   -s: test if this is a file and if it has a size.
-            -   run: test -s result/diplom.pdf
+  # Builds the Nix derivation.
+  nix_build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v24
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+      - run: nix-build
+      #   -s: test if this is a file and if it has a size.
+      - run: test -s result/diplom.pdf
+
+  # Tests the regular build but with a toolchain from the Nix shll.
+  nix_shell:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v24
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+      - run: nix-shell --run "make"
+      - run: nix-shell --run "make stats"
 
-    # uses latexmk
-    regular_build:
-        runs-on: ubuntu-latest
-        steps:
-            -   name: Set up Git repository
-                uses: actions/checkout@v2
-            -   name: Compile LaTeX document
-                uses: xu-cheng/latex-action@v2
-                with:
-                    # options listed here:
-                    # https://github.com/xu-cheng/latex-action
-                    root_file: diplom.tex
-                    latexmk_use_lualatex: true
-                    # required when using the "minted" package for beautiful styled code
-                    # latexmk_shell_escape: true
+  # Builds with a regular toolchain via latexmk.
+  regular_build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Git repository
+        uses: actions/checkout@v4
+      - name: Compile LaTeX document
+        uses: xu-cheng/latex-action@v2
+        with:
+          # options listed here:
+          # https://github.com/xu-cheng/latex-action
+          root_file: diplom.tex
+          latexmk_use_lualatex: true
+          # required when using the "minted" package for beautiful styled code
+          # latexmk_shell_escape: true
 
-    # checkbiw and check-french-spacing must execute without error
-    check_scripts:
-        runs-on: ubuntu-latest
-        steps:
-            -   name: Set up Git repository
-                uses: actions/checkout@v2
-                # additionally: check out submodules
-                with:
-                    submodules: recursive
-            -   name: install make
-                run: sudo apt update && sudo apt install make
-            -   name: make check-french-spacing
-                run: make check-french-spacing
-            -   name: install diction
-                run: sudo apt update && sudo apt install diction
-            -   name: make checkbiw
-                run: make checkbiw
+  # checkbiw and check-french-spacing must execute without error
+  check_scripts:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Git repository
+        uses: actions/checkout@v4
+        # additionally: check out submodules
+        with:
+          submodules: recursive
+      - name: install make
+        run: sudo apt update && sudo apt install make
+      - name: make check-french-spacing
+        run: make check-french-spacing
+      - name: install diction
+        run: sudo apt update && sudo apt install diction
+      - name: make checkbiw
+        run: make checkbiw