[gardening] Mark test slow

(Apparently the other test doesn't exist anymore, and normalize
automatically removed it.)

Bug: #56979
Bug: #60067
Change-Id: I934c6dc4041925631de31d1832e4946002b411b9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/408300
Reviewed-by: Tess Strickland <[email protected]>
Auto-Submit: Daco Harkes <[email protected]>
Commit-Queue: Tess Strickland <[email protected]>

Author: dcharkes

pkg/pkg.status

@@ -9,7 +9,6 @@
 */*/*/packages/*/*: Skip
 */*/packages/*/*: Skip
 */packages/*/*: Skip
-analyzer/test/src/summary/macro_test: Slow, Pass
 analyzer/test/verify_diagnostics_test: Slow, Pass
 analyzer/test/verify_docs_test: Slow, Pass
 analyzer_plugin/test/plugin/folding_mixin_test: Slow, Pass
@@ -72,6 +71,7 @@ vm_service/test/get_cpu_samples_rpc_test: Slow, Pass # Does some computation to
 vm_service/test/get_perfetto_cpu_samples_rpc_test: Slow, Pass # Does some computation to ensure CPU samples are collected.
 vm_service/test/reload_sources_with_resident_compiler_test: Skip # issue 59909
 vm_service/test/valid_source_locations_test: ExtraSlow, Pass # Iterates through all libraries and checks for valid source locations.
+vm_snapshot_analysis/test/instruction_sizes_test: Pass, Slow # https://github.com/dart-lang/sdk/issues/60067
 wasm/*: SkipByDesign # These can't be run without running wasm:setup first.
 
 [ $compiler == dart2analyzer ]