Cargo.toml: suppress resolver warning on nightly

```
warning: some crates are on edition 2021 which defaults to `resolver = "2"`, but virtual workspaces default to `resolver = "1"`
```

Cargo.toml

@@ -19,6 +19,7 @@ members = [
     "bpf/aya-log-ebpf",
     "test/integration-ebpf",
 ]
+resolver = "2"
 
 default-members = [
     "aya",

aya-log-parser/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "aya-log-parser"
 version = "0.1.11-dev.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 aya-log-common = { path = "../aya-log-common" }

bpf/aya-bpf-cty/Cargo.toml

@@ -1,5 +1,6 @@
 [package]
 authors = ["Jorge Aparicio <jorge@japaric.io>"]
+edition = "2021"
 categories = ["embedded", "external-ffi-bindings" ,"no-std"]
 description = "Type aliases to C types like c_int for use with bindgen"
 documentation = "https://docs.rs/cty"

bpf/aya-bpf-cty/src/lib.rs

@@ -46,7 +46,7 @@ mod ad {
     target_arch = "riscv64"
 ))]
 mod ad {
-    pub type c_char = ::c_uchar;
+    pub type c_char = super::c_uchar;
 
     pub type c_int = i32;
     pub type c_uint = u32;
@@ -63,7 +63,7 @@ mod ad {
     target_arch = "xtensa"
 ))]
 mod ad {
-    pub type c_char = ::c_schar;
+    pub type c_char = super::c_schar;
 
     pub type c_int = i32;
     pub type c_uint = u32;
@@ -71,7 +71,7 @@ mod ad {
 
 #[cfg(target_arch = "msp430")]
 mod ad {
-    pub type c_char = ::c_uchar;
+    pub type c_char = super::c_uchar;
 
     pub type c_int = i16;
     pub type c_uint = u16;