C#: Remove the 'security' tag from some queries

These queries are only tenuously security queries, and marking them as
security queries can cause them to have greater prominence than is
merited by the results that they report.

Author: lcartey

csharp/ql/src/API Abuse/DisposeNotCalledOnException.ql

@@ -9,7 +9,6 @@
  * @id cs/dispose-not-called-on-throw
  * @tags efficiency
  *       maintainability
- *       security
  *       external/cwe/cwe-404
  *       external/cwe/cwe-459
  *       external/cwe/cwe-460

csharp/ql/src/API Abuse/NoDisposeCallOnLocalIDisposable.ql

@@ -8,7 +8,6 @@
  * @id cs/local-not-disposed
  * @tags efficiency
  *       maintainability
- *       security
  *       external/cwe/cwe-404
  *       external/cwe/cwe-459
  *       external/cwe/cwe-460

csharp/ql/src/Likely Bugs/PossibleLossOfPrecision.ql

@@ -8,7 +8,6 @@
  * @id cs/loss-of-precision
  * @tags reliability
  *       correctness
- *       security
  *       external/cwe/cwe-190
  *       external/cwe/cwe-192
  *       external/cwe/cwe-197