feat: add PHP to list of telemetry libraries (#278)

## Which problem is this PR solving?

- lack of visibility into php library usage

## Short description of the changes

- add PHP instrumentation library prefix 
- fix typo in test for `telemetry.instrumentation_name`

otlp/common.go

@@ -77,6 +77,7 @@ var (
 		"OpenTelemetry::Instrumentation",              // Ruby
 		"go.opentelemetry.io/contrib/instrumentation", // Go
 		"@opentelemetry/instrumentation",              // JS
+		"io.opentelemetry.contrib.php",                // PHP
 	}
 )
 

otlp/traces_test.go

@@ -1107,7 +1107,7 @@ func TestInstrumentationLibrarySpansHaveAttributeAdded(t *testing.T) {
 	assert.Equal(t, "test_span_a", first_event.Attributes["name"])
 	assert.Equal(t, "First", first_event.Attributes["library.name"])
 	assert.Equal(t, "1.1.1", first_event.Attributes["library.version"])
-	assert.NotContains(t, first_event.Attributes, "telemtetry.instrumentation_library")
+	assert.NotContains(t, first_event.Attributes, "telemetry.instrumentation_library")
 	second_event := events[1]
 	assert.Equal(t, "test_span_b", second_event.Attributes["name"])
 	assert.Equal(t, "io.opentelemetry.instrumentation.http", second_event.Attributes["library.name"])
@@ -1161,6 +1161,11 @@ func TestKnownInstrumentationPrefixesReturnTrue(t *testing.T) {
 			libraryName:              "@opentelemetry/instrumentation/http",
 			isInstrumentationLibrary: true,
 		},
+		{
+			name:                     "php",
+			libraryName:              "io.opentelemetry.contrib.php.slim",
+			isInstrumentationLibrary: true,
+		},
 	}
 
 	for _, test := range tests {