Signed-off-by: Thomas Böhler <witcher@wiredspace.de>

Signed-off-by: Thomas Böhler <witcher@wiredspace.de>

The `open64` function on musl is not available anymore as `off_t` has always been 64-bit for musl. This enables building for newer musl versions again. More information: https://github.com/rust-random/getrandom/pull/326 https://git.musl-libc.org/cgit/musl/commit/?id=246f1c811448f37a44b41cd8df8d0ef9736d95f4 Signed-off-by: Thomas Böhler <witcher@wiredspace.de>

More information: https://rust-lang.github.io/rust-clippy/master/index.html#/lines_filter_map_ok Signed-off-by: Thomas Böhler <witcher@wiredspace.de>

With SNAFU, a context as well as a message can be given. It is similar to thiserror. Start using this to give meaningful errors without relying on anyhow.

Implements: https://todo.sr.ht/~witcher/rss-email/27 Implements: https://todo.sr.ht/~witcher/rss-email/26

Using rust on alpine is a pain, so just build on Arch Linux instead

Release mode builds are not necessary anymore as no artifacts are published. Helps CI load. Additionally, no docs are built either for the same reason.

No tests presently exist for this package, so take some load off CI by removing running tests entirely

cocogitto, with its binary `cog`, helps in me not messing any bumps in releases up anymore. In addition, all new tags, starting with the next version, now have a `v` prefix. https://github.com/cocogitto/cocogitto/

The version number in Cargo.toml was not updated from 0.3.0 to 0.4.0 in the 0.4.0 release, this is "fixed" with a new patch release bumping the version.