interface: Remove from the repo (#55)

#### Problem

As part of the upgrade to SDK v3, the cyclical dependency between the
sdk crates and the system interface were too much of an annoyance, so
the interface was migrated back into the SDK with
anza-xyz/solana-sdk#264. But the interface code
still lives in this repo as well.

#### Summary of changes

Remove the interface crate and all references to it.

Author: joncinque

.github/workflows/main.yml

@@ -48,68 +48,6 @@ jobs:
       - name: Lint / Features
         run: make lint-features-clients-rust
 
-  format_and_lint_interface:
-    name: Format & Lint Interface
-    runs-on: ubuntu-latest
-    steps:
-      - name: Git Checkout
-        uses: actions/checkout@v4
-
-      - name: Setup Environment
-        uses: ./.github/actions/setup
-        with:
-          toolchain: format, lint
-
-      - name: Format
-        run: make format-interface
-
-      - name: Lint / Clippy
-        run: make clippy-interface
-
-      - name: Lint / Docs
-        run: make lint-docs-interface
-
-      - name: Lint / Features
-        run: make lint-features-interface
-
-  wasm_interface:
-    name: Build Interface in WASM
-    runs-on: ubuntu-latest
-    steps:
-      - name: Git Checkout
-        uses: actions/checkout@v4
-
-      - name: Setup Environment
-        uses: ./.github/actions/setup
-        with:
-          cargo-cache-key: cargo-wasm-interface
-          solana: true
-
-      - name: Install wasm-pack
-        uses: taiki-e/install-action@v2
-        with:
-          tool: wasm-pack
-
-      - name: Build Interface with wasm-pack
-        run: make build-wasm-interface
-
-  test_interface:
-    name: Test Interface
-    runs-on: ubuntu-latest
-    steps:
-      - name: Git Checkout
-        uses: actions/checkout@v4
-
-      - name: Setup Environment
-        uses: ./.github/actions/setup
-        with:
-          toolchain: test
-          cargo-cache-key: cargo-interface
-          solana: true
-
-      - name: Test Interface
-        run: make test-interface
-
   generate_clients:
     name: Check Client Generation
     runs-on: ubuntu-latest

Cargo.toml

@@ -2,7 +2,6 @@
 resolver = "2"
 members = [
     "clients/rust",
-    "interface",
 ]
 
 [workspace.package]

Makefile

@@ -17,9 +17,6 @@ features-%:
 publish-%:
 	./scripts/publish-rust.sh $(subst -,/,$*)
 
-build-wasm-interface:
-	wasm-pack build --target nodejs --dev ./interface --features bincode
-
 lint-docs-%:
 	RUSTDOCFLAGS="--cfg docsrs -D warnings" cargo $(nightly) doc --all-features --no-deps --manifest-path $(subst -,/,$*)/Cargo.toml