use all-features devshell for clippy/all in CI

Without this, we're building a static rocksdb inside the rust-rocksdb
build script every time. As far as I know this doesn't change clippy's
behavior, but it does take a *long* time.

.envrc

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-use flake
+use flake ".#${DIRENV_DEVSHELL:-default}"
 
 PATH_add bin
 

bin/nix-build-and-cache

@@ -51,6 +51,7 @@ ci() {
 
         # Keep sorted
         "$toplevel#devShells.x86_64-linux.default"
+        "$toplevel#devShells.x86_64-linux.all-features"
         attic#default
         nixpkgs#direnv
         nixpkgs#jq

engage.toml

@@ -68,7 +68,9 @@ script = "cargo clippy --workspace --all-targets --color=always -- -D warnings"
 name = "cargo-clippy/all"
 group = "lints"
 script = """
-cargo clippy \
+env DIRENV_DEVSHELL=all-features \
+    direnv exec . \
+    cargo clippy \
         --workspace \
         --all-targets \
         --all-features \