⚰️🧪Remove DisableParallelizationCollectionFixture for some tests

Only tests that manipulate the global, static `UnitsNetSetup.Default.UnitAbbreviations` need to disable parallelization, changes to CurrentCulture is thread-static and is not flaky as long as each test reverts their changes with `CultureScope` or try-finally.

Author: angularsen

UnitsNet.Tests/CustomCode/LengthTests.cs

@@ -8,10 +8,6 @@
 
 namespace UnitsNet.Tests
 {
-    // Avoid accessing static prop DefaultToString in parallel from multiple tests:
-    // UnitSystemTests.DefaultToStringFormatting()
-    // LengthTests.ToStringReturnsCorrectNumberAndUnitWithCentimeterAsDefualtUnit()
-    [Collection(nameof(DisableParallelizationCollectionFixture))]
     public class LengthTests : LengthTestsBase
     {
         protected override bool SupportsSIUnitSystem => true;

UnitsNet.Tests/CustomCode/ParseTests.cs

@@ -15,7 +15,6 @@ namespace UnitsNet.Tests
     ///     reasonable to assume that testing one unit class would cover
     ///     all of them. Obviously, that can change in the future.
     /// </remarks>
-    [Collection(nameof(DisableParallelizationCollectionFixture))]
     public class ParseTests
     {
         [Theory]

UnitsNet.Tests/QuantityTests.ToString.cs

@@ -9,7 +9,6 @@
 
 namespace UnitsNet.Tests
 {
-    [Collection(nameof(DisableParallelizationCollectionFixture))]
     public partial class QuantityTests
     {
         public class ToStringTests

UnitsNet.Tests/UnitAbbreviationsCacheTests.cs

@@ -9,6 +9,7 @@
 
 namespace UnitsNet.Tests
 {
+    // Disable parallelization due to manipulating global state, like UnitAbbreviationsCache.Default.MapUnitToDefaultAbbreviation().
     [Collection(nameof(DisableParallelizationCollectionFixture))]
     public class UnitAbbreviationsCacheTests
     {
@@ -20,7 +21,7 @@ public class UnitAbbreviationsCacheTests
         private static readonly IFormatProvider NorwegianCulture = CultureInfo.GetCultureInfo(NorwegianCultureName);
         private static readonly IFormatProvider RussianCulture = CultureInfo.GetCultureInfo(RussianCultureName);
 
-        // The default, parameterless ToString() method uses 2 sigifnificant digits after the radix point.
+        // The default, parameterless ToString() method uses 2 significant digits after the radix point.
         [Theory]
         [InlineData(0, "0 m")]
         [InlineData(0.1, "0.1 m")]

UnitsNet.Tests/UnitParserTests.cs

@@ -9,7 +9,6 @@
 
 namespace UnitsNet.Tests
 {
-    [Collection(nameof(DisableParallelizationCollectionFixture))]
     public class UnitParserTests
     {
         [Theory]