Remove EasyBlock.exts_all

This is always equal to `self.exts` as skipping is done on
`self.ext_instances`.

easybuild/framework/easyblock.py

@@ -166,7 +166,6 @@ def __init__(self, ec):
 
         # extensions
         self.exts = []
-        self.exts_all = None
         self.ext_instances = []
         self.skip = None
         self.module_extra_extensions = ''  # extra stuff for module file required by extensions
@@ -1984,7 +1983,7 @@ def install_extensions_parallel(self, install=True):
         running_exts = []
         installed_ext_names = []
 
-        all_ext_names = [x['name'] for x in self.exts_all]
+        all_ext_names = [x['name'] for x in self.exts]
         self.log.debug("List of names of all extensions: %s", all_ext_names)
 
         # take into account that some extensions may be installed already
@@ -2893,8 +2892,6 @@ def extensions_step(self, fetch=False, install=True):
             self.update_exts_progress_bar("fetching extension sources/patches")
             self.exts = self.collect_exts_file_info(fetch_files=True)
 
-        self.exts_all = self.exts[:]  # retain a copy of all extensions, regardless of filtering/skipping
-
         # we really need a default class
         if not self.cfg['exts_defaultclass']:
             raise EasyBuildError("ERROR: No default extension class set for %s", self.name)