ci: Fixing some blantant mistakes

Forgot to set the env var for the `build` step on the workflow.
The env var `tag` for the `Makefile` is now filled from the past `git
tag`.

.github/workflows/lazarus.yaml

@@ -11,7 +11,7 @@ permissions:
 on:
 
   push:
-    branches: [ lazarus, add-changes-from-gus ]
+    branches: [ lazarus ]
     tags: [ "*" ]
     paths-ignore: [ "README.md", "LICENSE", "CHANGELOG.md", ".github/cliff.toml" ]
 
@@ -22,6 +22,8 @@ jobs:
 
     build:
         runs-on: ${{ matrix.operating-system }}
+        env:
+          GITHUB: 1
         strategy:
             fail-fast: false
             matrix:

Makefile

@@ -17,6 +17,7 @@ ifeq ($(origin GITHUB), undefined)
         $(error "secrets.mk not found! Please create it first.")
     endif
     include ./secrets.mk
+	tag := $(shell git describe --tags $(shell git rev-list --tags --max-count=1) 2>/dev/null || echo "v0.0.0")
 else
     # GITHUB is set — skip including secrets.mk
     $(info GITHUB is set, not loading secrets.mk)