chore: do not use sentinel errors when unneeded

- main reason being it's a burden to always define sentinel errors at global scope, wrap them with `%w` instead of using a string directly
- only use sentinel errors when it has to be checked using `errors.Is`
- replace all usage of these sentinel errors in `fmt.Errorf` with direct strings that were in the sentinel error
- exclude the sentinel error definition requirement from .golangci.yml
- update unit tests to use ContainersError instead of ErrorIs so it stays as a "not a change detector test" without requiring a sentinel error

internal/mod/info_linux.go

@@ -181,8 +181,6 @@ func getLoadedModules(modulesInfo map[string]moduleInfo) (err error) {
 	return nil
 }
 
-var ErrModulePathNotFound = errors.New("module path not found")
-
 func findModulePath(moduleName string, modulesInfo map[string]moduleInfo) (modulePath string, err error) {
 	// Kernel module names can have underscores or hyphens in their names,
 	// but only one or the other in one particular name.
@@ -205,5 +203,5 @@ func findModulePath(moduleName string, modulesInfo map[string]moduleInfo) (modul
 		}
 	}
 
-	return "", fmt.Errorf("%w: for %q", ErrModulePathNotFound, moduleName)
+	return "", fmt.Errorf("module path not found: for %q", moduleName)
 }