guix: Rename unsigned.tar.gz to codesigning.tar.gz

The tarballs used for codesigning are more than merely unsigned, they
also contain scripts and other data for codesigning. Rename them to
codesigning.tar.gz to distinguish from tarballs containing actually just
the unsigned binaries.

contrib/guix/libexec/codesign.sh

@@ -27,7 +27,7 @@ fi
 # Check that required environment variables are set
 cat << EOF
 Required environment variables as seen inside the container:
-    UNSIGNED_TARBALL: ${UNSIGNED_TARBALL:?not set}
+    CODESIGNING_TARBALL: ${CODESIGNING_TARBALL:?not set}
     DETACHED_SIGS_REPO: ${DETACHED_SIGS_REPO:?not set}
     DIST_ARCHIVE_BASE: ${DIST_ARCHIVE_BASE:?not set}
     DISTNAME: ${DISTNAME:?not set}
@@ -63,7 +63,7 @@ mkdir -p "$DISTSRC"
 (
     cd "$DISTSRC"
 
-    tar -xf "$UNSIGNED_TARBALL"
+    tar -xf "$CODESIGNING_TARBALL"
 
     mkdir -p codesignatures
     tar -C codesignatures -xf "$CODESIGNATURE_GIT_ARCHIVE"
@@ -105,7 +105,7 @@ mv --no-target-directory "$OUTDIR" "$ACTUAL_OUTDIR" \
 (
     cd /outdir-base
     {
-        echo "$UNSIGNED_TARBALL"
+        echo "$CODESIGNING_TARBALL"
         echo "$CODESIGNATURE_GIT_ARCHIVE"
         find "$ACTUAL_OUTDIR" -type f
     } | xargs realpath --relative-base="$PWD" \