Create rule S7445: env! should be preferred over option_env! (#4789)

* Create rule S7445

* Update RSPEC

---------

Co-authored-by: yassin-kammoun-sonarsource <yassin-kammoun-sonarsource@users.noreply.github.com>
Co-authored-by: yassin-kammoun-sonarsource <yassin.kammoun@sonarsource.com>

rules/S7445/metadata.json

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+{
+}

rules/S7445/rust/metadata.json

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+{
+  "title": "`env!` should be preferred over `option_env!`",
+  "type": "BUG",
+  "status": "ready",
+  "remediation": {
+    "func": "Constant\/Issue",
+    "constantCost": "5min"
+  },
+  "tags": [
+    "clippy"
+  ],
+  "defaultSeverity": "Major",
+  "ruleSpecification": "RSPEC-7445",
+  "sqKey": "S7445",
+  "scope": "All",
+  "defaultQualityProfiles": ["Sonar way"],
+  "quickfix": "unknown",
+  "code": {
+    "impacts": {
+      "RELIABILITY": "LOW"
+    },
+    "attribute": "LOGICAL"
+  }
+}

rules/S7445/rust/rule.adoc

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+== Why is this an issue?
+
+Unwrapping the result of `option_env!` will panic at runtime if the environment variable doesn't exist, whereas `env!` catches it at compile-time, ensuring safer code execution.
+
+=== Code examples
+
+==== Noncompliant code example
+
+[source,rust,diff-id=1,diff-type=noncompliant]
+---_
+let _ = option_env!("HOME").unwrap(); // Noncompliant: Can panic at runtime.
+---_
+
+==== Compliant solution
+
+[source,rust,diff-id=1,diff-type=compliant]
+---_
+let _ = env!("HOME"); // Compliant: Ensures compile-time checking.
+---_
+
+== Resources
+=== Documentation
+
+* Clippy Lints - https://rust-lang.github.io/rust-clippy/master/index.html#option_env_unwrap