Update Guix-Science channel URLs.

* head-node.scm (cuirass-specs): Update.
* plafrim/channels.pinned.scm: Update.

head-node.scm

@@ -100,7 +100,7 @@ export CUIRASS_LOGGING_LEVEL=${CUIRASS_LOGGING_LEVEL:-debug}\n"
            (channels
             (cons (channel
 	           (name 'guix-science)
-	           (url "https://github.com/guix-science/guix-science.git")
+	           (url "https://codeberg.org/guix-science/guix-science.git")
 	           (introduction
 	            (make-channel-introduction
 		     "b1fe5aaff3ab48e798a4cce02f0212bc91f423dc"
@@ -115,7 +115,7 @@ export CUIRASS_LOGGING_LEVEL=${CUIRASS_LOGGING_LEVEL:-debug}\n"
            (channels
             (cons (channel
 	           (name 'guix-science-nonfree)
-	           (url "https://github.com/guix-science/guix-science-nonfree.git")
+	           (url "https://codeberg.org/guix-science/guix-science-nonfree.git")
 	           (introduction
                     (make-channel-introduction
                      "58661b110325fd5d9b40e6f0177cc486a615817e"

plafrim/channels.pinned.scm

@@ -20,7 +20,7 @@
           "372c5f471448b32c9204f79c1d46e9b984d03c07"))
       (channel
         (name 'guix-science-nonfree)
-        (url "https://github.com/guix-science/guix-science-nonfree.git")
+        (url "https://codeberg.org/guix-science/guix-science-nonfree.git")
         (branch "master")
         (commit
           "9a3f3824d8ed289832d706679410edadac1202ae")