[BUG] False positive branch coverage of `if` without `else`

[carlreinke]

Describe the bug
When there is an if without an else and the condition is satisfied then it is possible to have 100% branch coverage without a test that does not satisfy the condition.

To Reproduce

namespace CoverageTest;

public static class Class1
{
    public static int Test1(int n)
    {
        if (n < 10)
            n = Random.Shared.Next();
        return n;
    }
}

using Xunit;

namespace CoverageTest.Tests;

public static class Class1Tests
{
    [Fact]
    public static void Test1()
    {
        Class1.Test1(2);
    }
}

Expected behavior
Branch is 50% covered.

Actual behavior

<Methods>
  <Method cyclomaticComplexity="2" nPathComplexity="2" sequenceCoverage="100" branchCoverage="100" isConstructor="False" isGetter="False" isSetter="False" isStatic="True">
    <Summary numSequencePoints="5" visitedSequencePoints="5" numBranchPoints="2" visitedBranchPoints="2" sequenceCoverage="100" branchCoverage="100" maxCyclomaticComplexity="2" minCyclomaticComplexity="2" visitedClasses="0" numClasses="0" visitedMethods="1" numMethods="1" />
    <MetadataToken />
    <Name>System.Int32 CoverageTest.Class1::Test1(System.Int32)</Name>
    <FileRef uid="1" />
    <SequencePoints>
      <SequencePoint vc="1" uspid="6" ordinal="0" sl="6" sc="1" el="6" ec="2" bec="0" bev="0" fileid="1" />
      <SequencePoint vc="1" uspid="7" ordinal="1" sl="7" sc="1" el="7" ec="2" bec="2" bev="2" fileid="1" />
      <SequencePoint vc="1" uspid="8" ordinal="2" sl="8" sc="1" el="8" ec="2" bec="0" bev="0" fileid="1" />
      <SequencePoint vc="1" uspid="9" ordinal="3" sl="9" sc="1" el="9" ec="2" bec="0" bev="0" fileid="1" />
      <SequencePoint vc="1" uspid="10" ordinal="4" sl="10" sc="1" el="10" ec="2" bec="0" bev="0" fileid="1" />
    </SequencePoints>
    <BranchPoints>
      <BranchPoint vc="1" uspid="7" ordinal="0" path="0" offset="8" offsetend="10" sl="7" fileid="1" />
      <BranchPoint vc="1" uspid="7" ordinal="1" path="1" offset="8" offsetend="22" sl="7" fileid="1" />
    </BranchPoints>
    <MethodPoint vc="5" uspid="0" p8:type="SequencePoint" ordinal="0" offset="0" sc="0" sl="6" ec="1" el="10" bec="0" bev="0" fileid="1" xmlns:p8="xsi" />
  </Method>

Configuration:

• Which coverlet package and version was used? coverlet.collector 6.0.4 and coverlet.msbuild 6.0.4
• Which version of .NET is the code running on? .NET 10.0.0
• What OS and version, and what distro if applicable? Windows 10.0.26100 Build 26100
• What is the architecture (x64, x86, ARM, ARM64)? x64
• Do you know whether it is specific to that configuration? Likely not.

Additional context
There was #1028, but it was closed as stale.