Create make target for testing reproducible builds

Migrate the logic of the reproducible build check from CI to the
Makefile in order to make it convenient to run the test offline too. The
CI now uses this new make target to avoid duplication of the test logic.

Signed-off-by: Eric Cornelissen <ericornelissen@gmail.com>

.github/workflows/check.yml

@@ -94,16 +94,8 @@ jobs:
       uses: actions/setup-go@cdcb36043654635271a94b9a6d1392de5bb323a7 # v5.0.1
       with:
         go-version-file: go.mod
-    - name: Build
-      run: make build
-    - name: Compute checksum
-      run: shasum ades | tee checksums.txt
-    - name: Clear build
-      run: make clean
-    - name: Rebuild
-      run: make build
-    - name: Verify checksum
-      run: shasum --check checksums.txt --strict
+    - name: Check reproducibility
+      run: make reproducible
   test-unit:
     name: Unit test
     runs-on: ubuntu-22.04

Makefile

@@ -206,6 +206,13 @@ release-compile:
 	@echo 'Computing checksums...'
 	@cd _compiled/ && shasum --algorithm 512 ./* >'checksums-sha512.txt'
 
+.PHONY: reproducible
+reproducible:
+	@make build
+	@shasum ades | tee checksums.txt
+	@make clean build
+	@shasum --check checksums.txt --strict
+
 .PHONY: run
 run: ## Run the project on itself
 	@go run ./cmd/ades