[linear][istlsolverfactorybackend] Make usable with dune 2.7
See merge request !1982 (merged)
(cherry picked from commit 07488576)
947f1b32 [linear][istlsolverfactorybackend] Make usable with dune 2.7
[linear][istlsolverfactorybackend] Make usable with dune 2.7
See merge request !1982 (merged)
(cherry picked from commit 07488576)
947f1b32 [linear][istlsolverfactorybackend] Make usable with dune 2.7