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.

doc/release-process.md

@@ -164,7 +164,7 @@ Then open a Pull Request to the [guix.sigs repository](https://github.com/bitcoi
 
 In the `guix-build-${VERSION}/output/x86_64-apple-darwin` and `guix-build-${VERSION}/output/arm64-apple-darwin` directories:
 
-    tar xf bitcoin-osx-unsigned.tar.gz
+    tar xf bitcoin-${VERSION}-${ARCH}-apple-darwin-codesigning.tar.gz
     ./detached-sig-create.sh /path/to/codesign.p12
     Enter the keychain password and authorize the signature
     signature-osx.tar.gz will be created
@@ -173,7 +173,7 @@ In the `guix-build-${VERSION}/output/x86_64-apple-darwin` and `guix-build-${VERS
 
 In the `guix-build-${VERSION}/output/x86_64-w64-mingw32` directory:
 
-    tar xf bitcoin-win-unsigned.tar.gz
+    tar xf bitcoin-${VERSION}-win64-codesigning.tar.gz
     ./detached-sig-create.sh -key /path/to/codesign.key
     Enter the passphrase for the key when prompted
     signature-win.tar.gz will be created