refactor: remove dead code and consolidate tests (#1335)

Removes dead code and redundant logic and consolidates tests, so there is less to read and maintain. No behavior change.

1. **act/runner**: inline single-use wrappers, compile regexes once instead of per call, embed the trampoline as a string, drop the unused legacy result of `parseActionCommand`
2. **act/container**: `sanitizeConfig` and `mergeContainerConfigs` stop returning the configs they already mutate in place, drop never-set option fields and the unused `user` parameter of `ExecWithCmdLine`
3. **act/common and cache server**: drop the unused `Trace`/`Tracef` loggers and the short SHA of `FindGitRevision`, `RegisterJob` releases through `RevokeJob`
4. **daemon, poller and reporter**: one shutdown wait for both poll modes, drop an unreachable fetch timeout branch, guard the reporter's last report time with its existing lock instead of an atomic
5. **build**: drop unused Makefile and release workflow variables, collapse the goreleaser ignore list to the same build targets
6. **tests**: fold near-duplicate tests into tables with shared setup

Throughout, hand-rolled logic gives way to `cmp.Or`, `strings.Cut`, `slices` and `min`/`max`.

Reviewed-on: https://gitea.com/gitea/runner/pulls/1335
Reviewed-by: bircni <[email protected]>
Co-authored-by: silverwind <[email protected]>

Makefile

@@ -14,7 +14,6 @@ GOFILES := $(shell find . -type f -name "*.go" -o -name "go.mod" ! -name "genera
 DOCKER_IMAGE ?= gitea/runner
 DOCKER_TAG ?= nightly
 DOCKER_REF := $(DOCKER_IMAGE):$(DOCKER_TAG)
-DOCKER_ROOTLESS_REF := $(DOCKER_IMAGE):$(DOCKER_TAG)-dind-rootless
 
 GOLANGCI_LINT_PACKAGE ?= github.com/golangci/golangci-lint/v2/cmd/[email protected] # renovate: datasource=go
 GOVULNCHECK_PACKAGE ?= golang.org/x/vuln/cmd/[email protected] # renovate: datasource=go
@@ -34,15 +33,12 @@ endif
 
 ifeq ($(OS), Windows_NT)
 	GOFLAGS := -v -buildmode=exe
-	EXECUTABLE ?= $(EXECUTABLE).exe
 	GO_ENV_WINDOWS := set GOOS=windows&&
 else ifeq ($(OS), Windows)
 	GOFLAGS := -v -buildmode=exe
-	EXECUTABLE ?= $(EXECUTABLE).exe
 	GO_ENV_WINDOWS := set GOOS=windows&&
 else
 	GOFLAGS := -v
-	EXECUTABLE ?= $(EXECUTABLE)
 	GO_ENV_WINDOWS := GOOS=windows
 endif