Merge bitcoin/bitcoin#34227: guix: Fix osslsigncode tests

194114daf3 guix: Fix `osslsigncode` tests (Hennadii Stepanov)

Pull request description:

  This PR aims to improve the experience for Guix builders when creating new Guix profiles after 2025. In particular, it should be helpful for those who are new to building with Guix.

  Fixes https://github.com/bitcoin/bitcoin/issues/34220.

  Other possible alternatives to consider include:
  1. Applying a workaround as suggested [here](https://github.com/bitcoin/bitcoin/issues/34220#issuecomment-3718991398).

  2. Updating the package as suggested [here](https://github.com/bitcoin/bitcoin/issues/34220#issuecomment-3719022287).

  3. Disabling tests as suggested [here](https://github.com/bitcoin/bitcoin/issues/34220#issuecomment-3719538660).

ACKs for top commit:
  fanquake:
    ACK 194114daf3 as a short-term, backportable workaround.
  janb84:
    ACK 194114daf3

Tree-SHA512: b263604297adfc54fccab8fe3c3126939b729aebda5b7e15f6f453a17260fd4ea754523a694bbc4268693513d071c4362325b0511696af2e81f00f1a461bcfa9

contrib/guix/manifest.scm

@@ -2,6 +2,7 @@
              ((gnu packages bash) #:select (bash-minimal))
              (gnu packages bison)
              ((gnu packages certs) #:select (nss-certs))
+             ((gnu packages check) #:select (libfaketime))
              ((gnu packages cmake) #:select (cmake-minimal))
              (gnu packages commencement)
              (gnu packages compression)
@@ -208,7 +209,17 @@ and abstract ELF, PE and MachO formats.")
                (base32
                 "1j47vwq4caxfv0xw68kw5yh00qcpbd56d7rq6c483ma3y7s96yyz"))))
     (build-system cmake-build-system)
-    (inputs (list openssl))
+    (arguments
+     (list
+      #:phases
+      #~(modify-phases %standard-phases
+          (replace 'check
+            (lambda* (#:key tests? #:allow-other-keys)
+              (if tests?
+                  (invoke "faketime" "-f" "@2025-01-01 00:00:00" ;; Tests fail after 2025.
+                          "ctest" "--output-on-failure" "--no-tests=error")
+                  (format #t "test suite not run~%")))))))
+    (inputs (list libfaketime openssl))
     (home-page "https://github.com/mtrojnar/osslsigncode")
     (synopsis "Authenticode signing and timestamping tool")
     (description "osslsigncode is a small tool that implements part of the