gnu: icu4c: Remove redundant icu4c-66.1 variable.

* gnu/packages/icu4c.scm (icu4c-66.1): Remove variable.
* gnu/packages/chromium.scm (ungoogled-chromium)[inputs]: Change from
ICU4C-66.1 to ICU4C.

gnu/packages/chromium.scm

@@ -786,7 +786,7 @@ from forcing GEXP-PROMISE."
        ("glib" ,glib)
        ("gtk+" ,gtk+)
        ("harfbuzz" ,harfbuzz)
-       ("icu4c" ,icu4c-66.1)
+       ("icu4c" ,icu4c)
        ("jsoncpp" ,jsoncpp)
        ("lcms" ,lcms)
        ("libevent" ,libevent)

gnu/packages/icu4c.scm

@@ -114,24 +114,6 @@ C/C++ part.")
                  #t)))))))
     (native-inputs '())))
 
-(define-public icu4c-66.1
-  (package
-    (inherit icu4c)
-    (version "66.1")
-    (source (origin
-              (method url-fetch)
-              (uri (string-append
-                    "https://github.com/unicode-org/icu/releases/download/release-"
-                    (string-map (lambda (x) (if (char=? x #\.) #\- x)) version)
-                    "/icu4c-"
-                    (string-map (lambda (x) (if (char=? x #\.) #\_ x)) version)
-                    "-src.tgz"))
-              (patch-flags '("-p2"))
-              (patches (search-patches "icu4c-CVE-2020-10531.patch"))
-              (sha256
-               (base32
-                "0bharwzc9nzkbrcf405z2nb3h7q0711z450arz0mjmdrk8hg58sj"))))))
-
 (define-public java-icu4j
   (package
     (name "java-icu4j")