inveniogc: clean up gc tasks

• Removes obsolete gc tasks (such as bibedit tmp files, bibreformat). (PR #1950)

• If CFG_INSPIRE_SITE=1, disables for INSPIRE non related gc tasks (BibSword, BibEncode...).

Signed-off-by: Samuele Kaplun <samuele.kaplun@cern.ch>
Tested-by: Tibor Simko <tibor.simko@cern.ch>