Document provider-facing breaking change: no-op SQL CAST stripping (#5351)

Refs dotnet/efcore#36247, dotnet/efcore#38156

Author: roji

entity-framework/core/what-is-new/ef-core-11.0/provider-facing-changes.md

@@ -14,6 +14,7 @@ This page documents noteworthy changes in EF Core 11 which may affect EF provide
 
 * Collation names are now quoted in SQL, like column and table names ([see #37462](https://github.com/dotnet/efcore/issues/37462)). If your database doesn't support collation name quoting, override `QuerySqlGenerator.VisitSql()` and `MigrationsSqlGenerator.ColumnDefinition()` to revert to the previous behavior, but it's recommended to implement some sort of restricted character validation.
 * The `JsonPath` property on `IColumnModification` and `ColumnModificationParameters` has changed from `string?` to the new structured `JsonPath` type ([PR #38038](https://github.com/dotnet/efcore/pull/38038)). The `JsonPath` class provides `Segments`, `Ordinals`, an `IsRoot` property, and an `AppendTo(StringBuilder)` method for rendering the JSONPATH string. Providers that override `UpdateSqlGenerator.AppendUpdateColumnValue()` or otherwise handle JSON partial updates should update their code to use this new type. Where previously you checked for `null` or `"$"`, use `JsonPath is not { IsRoot: false }` instead, and call `JsonPath.AppendTo(stringBuilder)` to write the JSONPATH string representation.
+* EF Core now strips no-op SQL CASTs - i.e. `SqlUnaryExpression(Convert)` nodes whose store type matches that of their operand ([see #36247](https://github.com/dotnet/efcore/issues/36247), [PR #38156](https://github.com/dotnet/efcore/pull/38156)). This can flush out imprecise translations which assigned an imprecise store type to a node and then wrapped it with a Convert; because the store types now match, the Convert is stripped, and the imprecise store type may propagate. Review your translations to ensure that the operand of a Convert node has the correct, precise store type.
 
 ## Test changes