perf: speed up job setup, action preparation and the cache server (#1327)

- Look up containers by name instead of listing all of them
- On Linux, cache the docker proxy discovery instead of starting a probe container per job
- Download a job's actions concurrently and share identical fetches between concurrent jobs
- Cache `runner.arch` per run and poll service health every 250ms
- Cache server: queue on an in-process lock instead of polling the database file lock, upload S3 objects up to 64MiB in one request and larger ones in 4 concurrent parts

| `exec`, median of 5 | Before | After |
|---|---:|---:|
| 1 step | 1.70s | 0.87s |
| 10 steps | 2.84s | 1.97s |
| Service + step | 3.78s | 2.18s |
| checkout + Node action | 3.64s | 2.52s |

Reviewed-on: https://gitea.com/gitea/runner/pulls/1327
Reviewed-by: Zettat123 <[email protected]>

act/runner/step.go

@@ -165,11 +165,14 @@ func runStepExecutor(step step, stage stepStage, executor common.Executor) commo
 		if topRC.summaryFileInitialized == nil {
 			topRC.summaryFileInitialized = map[int]bool{}
 		}
-		_ = rc.JobContainer.Copy(actPath, files...)(ctx)
+		initialFiles := files
 		if !topRC.summaryFileInitialized[stepSummaryIndex] {
-			_ = rc.JobContainer.Copy(actPath, &container.FileEntry{Name: summaryFileCommand, Mode: 0o666})(ctx)
+			initialFiles = append([]*container.FileEntry{{Name: summaryFileCommand, Mode: 0o666}}, files...)
 			topRC.summaryFileInitialized[stepSummaryIndex] = true
 		}
+		if err := rc.JobContainer.Copy(actPath, initialFiles...)(ctx); err != nil && len(initialFiles) > len(files) {
+			_ = rc.JobContainer.Copy(actPath, files...)(ctx) // the summary goes first and the resets retry alone, so neither failure blocks the other
+		}
 
 		// The command handler needs the step's env to judge ACTIONS_ALLOW_UNSECURE_COMMANDS.
 		// Cloned: the step executor keeps writing to its own env map after this point, on a