Remove old libfuzzer dotnet template (#2875)

### Context
The original `libfuzzer dotnet` job template was a proof of concept that demonstrated how the `libfuzzer_fuzz` task could be used to express fuzzing via the (pre SharpFuzz 2.0) `libfuzzer-dotnet` tool. It (and its associated integration test) used a harness that linked an older version of SharpFuzz, and which is incompatible with LibFuzzerDotnetLoader (which requires SharpFuzz 2.0 or greater).

### Changes
- Rename `libfuzzer dotnet_dll` job template to `libfuzzer dotnet`, making it the _only_ `libfuzzer-dotnet` template
- Remove integration tests and docs for the old proof-of-concept job type

### Notice

This is a breaking change.

Closes #2874.

src/integration-tests/integration-test.py

@@ -59,7 +59,6 @@ class TaskTestState(Enum):
 class TemplateType(Enum):
     libfuzzer = "libfuzzer"
     libfuzzer_dotnet = "libfuzzer_dotnet"
-    libfuzzer_dotnet_dll = "libfuzzer_dotnet_dll"
     libfuzzer_qemu_user = "libfuzzer_qemu_user"
     afl = "afl"
     radamsa = "radamsa"
@@ -153,16 +152,6 @@ TARGETS: Dict[str, Integration] = {
     "linux-libfuzzer-dotnet": Integration(
         template=TemplateType.libfuzzer_dotnet,
         os=OS.linux,
-        target_exe="wrapper",
-        nested_setup_dir="my-fuzzer",
-        inputs="inputs",
-        use_setup=True,
-        wait_for_files={ContainerType.inputs: 2, ContainerType.crashes: 1},
-        test_repro=False,
-    ),
-    "linux-libfuzzer-dotnet-dll": Integration(
-        template=TemplateType.libfuzzer_dotnet_dll,
-        os=OS.linux,
         setup_dir="GoodBadDotnet",
         target_exe="GoodBadDotnet/GoodBad.dll",
         target_options=["-max_len=4", "-only_ascii=1", "-seed=1"],
@@ -245,8 +234,8 @@ TARGETS: Dict[str, Integration] = {
         },
         use_setup=True,
     ),
-    "windows-libfuzzer-dotnet-dll": Integration(
-        template=TemplateType.libfuzzer_dotnet_dll,
+    "windows-libfuzzer-dotnet": Integration(
+        template=TemplateType.libfuzzer_dotnet,
         os=OS.windows,
         setup_dir="GoodBadDotnet",
         target_exe="GoodBadDotnet/GoodBad.dll",