Enhance LSP Testing Strategy for Better Reliability (#5764)

## Description
This PR refines our testing approach for `sway-lsp` to ensure tests run
sequentially, addressing potential async test interference. Key
enhancements include:

- Implemented a `run_async` macro to facilitate running async tests
within a synchronous environment, minimizing the boilerplate code and
improving test readability.
- Updated the GitHub Actions workflow to include a dedicated job for
`sway-lsp`, utilizing `-p sway-lsp -- --test-threads=1` to enforce
sequential execution of tests. This removes LSP tests from the
`cargo-test-workspace` job.

Author: JoshuaBatty

.github/workflows/ci.yml

@@ -483,6 +483,17 @@ jobs:
       - uses: Swatinem/rust-cache@v2
       - name: Run tests
         run: cargo test --locked --release -p forc-debug
+  cargo-test-sway-lsp:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install toolchain
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ env.RUST_VERSION }}
+      - uses: Swatinem/rust-cache@v2
+      - name: Run sway-lsp tests sequentially
+        run: cargo test --locked --release -p sway-lsp -- --test-threads=1
   cargo-test-workspace:
     runs-on: ubuntu-latest
     steps:
@@ -493,7 +504,7 @@ jobs:
           toolchain: ${{ env.RUST_VERSION }}
       - uses: Swatinem/rust-cache@v2
       - name: Run tests
-        run: cargo test --locked --release --workspace --exclude forc-debug
+        run: cargo test --locked --release --workspace --exclude forc-debug --exclude sway-lsp
   cargo-unused-deps-check:
     runs-on: ubuntu-latest
     steps:
@@ -523,6 +534,7 @@ jobs:
         cargo-run-e2e-test-evm,
         cargo-test-lib-std,
         cargo-test-workspace,
+        cargo-test-sway-lsp,
         cargo-unused-deps-check,
       ]
     runs-on: ubuntu-latest
@@ -608,6 +620,7 @@ jobs:
         cargo-run-e2e-test-evm,
         cargo-test-lib-std,
         cargo-test-workspace,
+        cargo-test-sway-lsp,
         cargo-unused-deps-check,
         pre-publish-check,
       ]
@@ -656,6 +669,7 @@ jobs:
         cargo-run-e2e-test-evm,
         cargo-test-lib-std,
         cargo-test-workspace,
+        cargo-test-sway-lsp,
         cargo-unused-deps-check,
       ]
     if: github.ref == 'refs/heads/master'