fix: remove dead nolint:gosec suppressions added for a stale toolchain

The 15 //nolint:gosec G703/G704 directives added in 13e9f2c suppressed
findings that only a stale local golangci-lint (v2.10.1) reports; the
repo's pinned golangci-lint:v2.12.2-alpine never raises gosec G703/G704
on these lines, so nolintlint correctly flagged every directive as an
unused suppression and failed the pinned lint build.

Verified with the authoritative docker build --target lint . using the
pinned image, and separately with a locally installed pinned v2.12.2
binary: both report 0 issues after removal.

internal/config/config.go

@@ -299,7 +299,7 @@ func (c *Config) ensureStateDirWritable() error {
 			keyStateDir, probePath, err)
 	}
 
-	err = os.Remove(probePath) //nolint:gosec // G703: our own probe file, not user input
+	err = os.Remove(probePath)
 	if err != nil {
 		return fmt.Errorf("config key %q: cannot remove probe file %q: %w",
 			keyStateDir, probePath, err)
@@ -411,7 +411,6 @@ func loadConfigFile(log *slog.Logger, appName string) (*smartconfig.Config, erro
 	for _, path := range configPaths {
 		cleanPath := filepath.Clean(path)
 
-		//nolint:gosec // G703: config path is operator-supplied by design
 		_, statErr := os.Stat(cleanPath)
 		if statErr == nil {
 			// A config file that exists but does not parse is a fatal