Build only libzim dependencies on bionic.

We compile only libzim on bionic, for compatibility with old libc.
No need to compile all other dependencies (and fight with some of them not
compiling)

kiwixbuild/dependencies/all_dependencies.py

@@ -1,3 +1,5 @@
+from os import environ
+
 from .base import (
     Dependency,
     NoopSource,
@@ -12,7 +14,7 @@ class AllBaseDependencies(Dependency):
     class Builder(NoopBuilder):
         @classmethod
         def get_dependencies(cls, platformInfo, allDeps):
-            if platformInfo.build == "wasm":
+            if platformInfo.build == "wasm" or environ.get('OS_NAME') == 'bionic':
                 return ['zlib', 'lzma', 'zstd', 'icu4c', 'xapian-core']
 
             base_deps = ['zlib', 'lzma', 'zstd', 'xapian-core', 'pugixml', 'libcurl', 'icu4c', 'mustache', 'libmicrohttpd', 'zim-testing-suite']