Consolidate GitHub CI actions, split out Monero (#71)

* Consolidate GitHub CI actions, split out Monero

build now includes the specified Rust toolchain/components.

Added a test dependencies action which grabs Foundry and Monero.

Split the Monero v14 job into a matrixed job in its own workflow flow. 
It's now only run when Monero has changes.

* Correct Monero unit/integration tests run timing

Additionally tests a feature-less Monero build.

Also removes a pointless Monero file, which already should have been 
removed, causing this workflow to be triggered.

* Correct exclusion and paths

Updates to FROST should re-run the Monero tests to ensure it didn't 
introduce API incompatibilities.

.github/workflows/monero-tests.yaml

@@ -0,0 +1,57 @@
+name: Monero Tests
+
+on:
+  push:
+    branches:
+      - develop
+    paths:
+      - "coins/monero/**"
+
+  pull_request:
+    paths:
+      - "coins/monero/**"
+
+jobs:
+  # Only run these once since they will be consistent regardless of any node
+  unit-tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          submodules: "recursive"
+
+      - name: Test Dependencies
+        uses: ./.github/actions/test-dependencies
+
+      - name: Run Unit Tests Without Features
+        run: cargo test --package monero-serai --lib
+
+      - name: Run Unit Tests
+        run: cargo test --package monero-serai --all-features --lib
+
+  integration-tests:
+    runs-on: ubuntu-latest
+    # Test against all supported protocol versions
+    strategy:
+      matrix:
+        version: [v0.17.3.2, v0.18.0.0]
+
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          submodules: "recursive"
+
+      - name: Test Dependencies
+        uses: ./.github/actions/test-dependencies
+        with:
+          monero-version: ${{ matrix.version }}
+
+      - name: Run Integration Tests Without Features
+        run: cargo test --package monero-serai --test '*'
+
+      - name: Run Integration Tests
+        # https://github.com/rust-lang/cargo/issues/8396
+        run: cargo test --package monero-serai --all-features --test '*'
+
+      - name: Run Processor's Monero Tests
+        run: cargo test --package serai-processor monero