ci: improve error checking (errcheck linter) (#11195)

## Description

Implements part of #7258

Check some of currently unchecked errors.

- [x] baseapp
- [x] client
- [x] codec
- [x] crypto
- [x] server
- [x] simapp
- [ ] snapshots
- [ ] store
- [x] testutil
- [ ] types
- [ ] modules

---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

testutil/ioutil_test.go

@@ -27,7 +27,7 @@ func TestApplyMockIO(t *testing.T) {
 
 func TestWriteToNewTempFile(t *testing.T) {
 	tempfile := testutil.WriteToNewTempFile(t, "test string")
-	tempfile.Close()
+	require.NoError(t, tempfile.Close())
 
 	bs, err := os.ReadFile(tempfile.Name())
 	require.NoError(t, err)

testutil/rest/rest.go

@@ -16,7 +16,9 @@ func GetRequest(url string) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer res.Body.Close()
+	defer func() {
+		_ = res.Body.Close()
+	}()
 
 	body, err := io.ReadAll(res.Body)
 	if err != nil {
@@ -33,7 +35,9 @@ func PostRequest(url string, contentType string, data []byte) ([]byte, error) {
 	if err != nil {
 		return nil, fmt.Errorf("error while sending post request: %w", err)
 	}
-	defer res.Body.Close()
+	defer func() {
+		_ = res.Body.Close()
+	}()
 
 	bz, err := io.ReadAll(res.Body)
 	if err != nil {