Create rule S2193: "while" loop counters should not have floating type (#4736)

* Add rust to rule S2193

* 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/S2193/rust/metadata.json

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+{
+  "title": "\"while\" loop counters should not have floating type",
+  "tags": [
+    "clippy"
+  ]
+}

rules/S2193/rust/rule.adoc

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+== Why is this an issue?
+
+When using a floating-point ``++while++`` loop counter, an accumulation of rounding errors may result in a mismatch between the expected and actual number of iterations.
+
+Even if floating-point loop counters appears to behave correctly on one implementation, it may give a different number of iterations on another implementation.
+
+== How to fix it
+
+To fix the issue, use an integer loop counter instead. This avoids the accumulation of rounding errors and ensures that the loop iterates the expected number of times.
+
+=== Code examples
+
+==== Noncompliant code example
+
+[source,rust,diff-id=1,diff-type=noncompliant]
+----
+fn main() {
+    let mut counter = 0.0;
+    while counter < 10.0 {
+        println!("Counter: {}", counter);
+        counter += 1.0;
+    }
+}
+----
+
+==== Compliant solution
+
+[source,rust,diff-id=1,diff-type=compliant]
+----
+fn main() {
+    let mut counter = 0;
+    while counter < 10 {
+        println!("Counter: {}", counter);
+        counter += 1;
+    }
+}
+----
+
+== Resources
+=== Documentation
+
+* Clippy Lints - https://rust-lang.github.io/rust-clippy/master/index.html#while_float