try to bump rust toolchain to 1.77

[r10s]

try to bump rust toolchain to 1.77

[r10s]

getting the following error:

[ERROR cargo_lipo] No package metadata found for "path+file:///Users/bpetersen/projects/deltachat-ios/deltachat-ios/libraries/deltachat-core-rust/deltachat-ffi#[email protected]"

there was sth. with "metadata" recently at TimNN/cargo-lipo#61 , i keep investigating ...

EDIT: the error can be reproduced by simple calling cargo lipo in deltachat-core-rust:

 ~/projects/deltachat-ios/deltachat-ios/libraries/deltachat-core-rust  (v1.136.6) % cargo +1.77.0 lipo          
[ERROR cargo_lipo] No package metadata found for "path+file:///Users/bpetersen/projects/deltachat-ios/deltachat-ios/libraries/deltachat-core-rust/deltachat-ffi#[email protected]"
 ~/projects/deltachat-ios/deltachat-ios/libraries/deltachat-core-rust  (v1.136.6) % cargo +1.73.0 lipo 
[INFO  cargo_lipo::meta] Will build universal library for ["deltachat_ffi"]
[INFO  cargo_lipo::lipo] Building "deltachat_ffi" for "aarch64-apple-ios"
   Compiling proc-macro2 v1.0.78
   Compiling libc v0.2.153
...

lipo version is 3.2.0 in both cases - according to TimNN/cargo-lipo#61, the issue is fixed in 3.3.0

in therory, a cargo install cargo-lipo in directory deltachat-ios/libraries/deltachat-core-rust should update and fix the issue.