Revert "Target .NET 8.0 for instrumentation tests"

This reverts commit d526168.

Author: bouwkast

tracer/test/Datadog.Trace.ClrProfiler.IntegrationTests/InstrumentationTests.cs

@@ -82,7 +82,7 @@ public async Task DoesNotInstrumentDotnetBuild()
 
             using var agent = EnvironmentHelper.GetMockAgent(useTelemetry: true);
 
-            var logDir = await RunDotnet("new console -n instrumentation_test -o . --no-restore -f net8.0");
+            var logDir = await RunDotnet("new console -n instrumentation_test -o . --no-restore");
             AssertNotInstrumented(agent, logDir);
 
             logDir = await RunDotnet("restore");
@@ -114,7 +114,7 @@ public async Task DoesNotInstrumentExcludedNames(string excludedProcess)
 
             using var agent = EnvironmentHelper.GetMockAgent(useTelemetry: true);
 
-            var logDir = await RunDotnet($"new console -n {excludedProcess} -o . --no-restore -f net8.0");
+            var logDir = await RunDotnet($"new console -n {excludedProcess} -o . --no-restore");
             AssertNotInstrumented(agent, logDir);
 
             var programCs = GetProgramCSThatMakesSpans();
@@ -152,7 +152,7 @@ public async Task DoesInstrumentAllowedProcesses(string allowedProcess)
 
             using var agent = EnvironmentHelper.GetMockAgent(useTelemetry: true);
 
-            var logDir = await RunDotnet($"new console -n {allowedProcess} -o . --no-restore -f net8.0");
+            var logDir = await RunDotnet($"new console -n {allowedProcess} -o . --no-restore");
             AssertNotInstrumented(agent, logDir);
             var programCs = GetProgramCSThatMakesSpans();
 
@@ -186,7 +186,7 @@ public async Task InstrumentsDotNetTest()
 
             using var agent = EnvironmentHelper.GetMockAgent(useTelemetry: true);
 
-            var logDir = await RunDotnet("new xunit -n instrumentation_test -o . --no-restore -f net8.0");
+            var logDir = await RunDotnet("new xunit -n instrumentation_test -o . --no-restore");
             AssertNotInstrumented(agent, logDir);
 
             // this _should_ be instrumented so we expect managed data.