fix: update MSRV to 1.78 to solve rust malfunction
This updated the rust MSRV to resolve a bug in the actual upstream rust
implementation that has been affecting eza for a while.
This obviously means new eza releases won't be available on all
distributions, but those distributions should move to a new version of
rust then, since this bug seems to indicate that there is an important
issue here.
Closes: #735
Refs: #666 https://github.com/rust-lang/rust/commit/e69f14b14cfa6e2ae863adb07e9add736d1f45fc
Signed-off-by: Christina Sørensen <ces@fem.gg>