chore: Add clippy lints (#529)

Lints are added (deny) at crate level.

In each offending file, the failing lints are explicitly allowed.
Each file will be fixed in subsequent PRs.

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

src/tests/interpreter/mod.rs

@@ -1,6 +1,17 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+#![allow(
+    clippy::panic,
+    clippy::panic_in_result_fn,
+    clippy::unwrap_used,
+    clippy::expect_used,
+    clippy::indexing_slicing,
+    clippy::semicolon_if_nothing_returned,
+    clippy::pattern_type_mismatch,
+    clippy::print_stderr
+)] // test harness asserts and unwraps to validate interpreter behavior
+
 use std::env;
 
 use crate::test_utils::{check_output, ValueOrVec};

src/tests/scheduler/analyzer/mod.rs

@@ -1,6 +1,17 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+#![allow(
+    clippy::panic,
+    clippy::panic_in_result_fn,
+    clippy::unwrap_used,
+    clippy::indexing_slicing,
+    clippy::std_instead_of_core,
+    clippy::semicolon_if_nothing_returned,
+    clippy::pattern_type_mismatch,
+    clippy::as_conversions
+)] // scheduler analyzer tests rely on asserts/unwraps and std conveniences
+
 use crate::*;
 use crate::{ast::*, lexer::*, parser::*, scheduler::*};
 use anyhow::{anyhow, bail, Result};

src/tests/scheduler/mod.rs

@@ -1,6 +1,12 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+#![allow(
+    clippy::panic_in_result_fn,
+    clippy::indexing_slicing,
+    clippy::as_conversions
+)] // scheduler tests assert and index directly for clarity
+
 use crate::scheduler::*;
 use crate::*;
 use anyhow::{bail, Result};