fix(docker): copy providers/ into in-Docker rust-builder stage

PR #1037 added include_str!("../../../providers/*.yaml") in
crates/openshell-providers/src/profiles.rs, but the BUILD_FROM_SOURCE=1
path of Dockerfile.images only COPY's Cargo.toml/Cargo.lock, crates/,
and proto/. With providers/ missing the cargo build inside the rust-
builder stage fails to read the embedded YAML. The release path is
unaffected because it copies pre-built binaries from
deploy/docker/.build/prebuilt-binaries/.

This breaks 'mise run e2e:helm:*' and any other workflow that builds
images from source via this Dockerfile (e.g., the local helm-e2e
harness). Add 'COPY providers/ providers/' alongside the other source
inputs.

Author: TaylorMutch

deploy/docker/Dockerfile.images

@@ -48,6 +48,7 @@ WORKDIR /build
 COPY Cargo.toml Cargo.lock ./
 COPY crates/ crates/
 COPY proto/ proto/
+COPY providers/ providers/
 
 RUN --mount=type=cache,target=/usr/local/cargo/registry \
     --mount=type=cache,target=/build/target \