Make all third-party github actions use hashes rather than tags

Author: cjhoward

.github/workflows/build.yml

@@ -27,7 +27,7 @@ jobs:
             # build_gen: "Unix Makefiles"
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
     - name: CMake configure 
       run: cmake -B build -G "${{matrix.build_gen}}" -A "${{matrix.build_arch}}"

.github/workflows/reuse.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
     - name: compliance check
-      uses: fsfe/reuse-action@v2
+      uses: fsfe/reuse-action@4f2804894b54004c8ed4b8a62b7c649e54a3aa4b # v2.0.0