sagemathgh-41190: Add boost-dev to Alpine package list in _prereqs
    
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This adds the full boost(dev) on alpine, a platform used to build binary
wheels - see e.g.
sagemath/pplpy#35

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URL: sagemath#41190
Reported by: Dima Pasechnik
Reviewer(s): Chenxin Zhong

Author: Release Manager

build/pkgs/_prereq/distros/alpine.txt

@@ -23,3 +23,4 @@ bzip2
 pkgconf
 zlib-dev
 boost
+boost-dev