gh-35083: build/pkgs/pcre: Remove
    
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### 📚 Description

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Remove the spkg `pcre`; it was a dependency of our `r` package, which
was reduced to a dummy package recently.
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Closes #32231

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URL: #35083
Reported by: Matthias Köppe
Reviewer(s): Dima Pasechnik

Author: Release Manager

build/pkgs/_prereq/distros/fedora.txt

@@ -30,7 +30,6 @@ gcc-c++
 # The need for which comes [...] from MPIR's configure script
 findutils
 which
-# Needed for pcre configure, see https://github.com/sagemath/sage/issues/29129:
 diffutils
 # Needed for openssl 3.0
 perl-IPC-Cmd