feat(cache): add shared S3-compatible storage (#1244)

Store the cache used by `actions/cache` in an S3-compatible bucket such as AWS S3 or RustFS, with no `cache-server`. Runners with the same settings use the same cache.

A cache saved on one runner can be restored on the others within 30 seconds. The runner talks to the bucket over the S3 REST API with SigV4, without an SDK. Lifecycle rules on the bucket expire old caches.

*Description rewritten by Claude.*

---------

Co-authored-by: silverwind <[email protected]>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1244
Reviewed-by: silverwind <[email protected]>
Co-authored-by: bircni <[email protected]>

go.mod

@@ -19,6 +19,7 @@ require (
 	github.com/go-git/go-billy/v5 v5.9.1
 	github.com/go-git/go-git/v5 v5.19.2
 	github.com/google/go-cmp v0.7.0
+	github.com/johannesboyne/gofakes3 v1.2.0
 	github.com/joho/godotenv v1.5.1
 	github.com/julienschmidt/httprouter v1.3.0
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
@@ -87,6 +88,7 @@ require (
 	github.com/pjbgf/sha1cd v0.6.0 // indirect
 	github.com/prometheus/common v0.70.1 // indirect
 	github.com/prometheus/procfs v0.21.1 // indirect
+	github.com/ryszard/goskiplist v0.0.0-20150312221310-2dfbae5fcf46 // indirect
 	github.com/santhosh-tekuri/jsonschema/v6 v6.0.3 // indirect
 	github.com/sergi/go-diff v1.4.0 // indirect
 	github.com/skeema/knownhosts v1.3.2 // indirect
@@ -95,7 +97,9 @@ require (
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.70.0 // indirect
 	go.opentelemetry.io/otel/metric v1.46.0 // indirect
+	go.shabbyrobe.org/gocovmerge v0.0.0-20230507111327-fa4f82cfbf4d // indirect
 	go.yaml.in/yaml/v3 v3.0.5 // indirect
 	golang.org/x/crypto v0.57.0 // indirect
+	golang.org/x/tools v0.49.0 // indirect
 	gopkg.in/warnings.v0 v0.1.2 // indirect
 )