fix: increase sdk.Dec maxApproxRootIterations (cosmos#12229)

## Description

`ApproxRoot` return incorrect value for large `sdk.Dec` because maxApproxRootIterations is not big enough, I increase it to 300

---

### Author Checklist

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- [ ] 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/main/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/main/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/main/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

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I have...

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

CHANGELOG.md

@@ -68,6 +68,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (types) [#12154](https://github.com/cosmos/cosmos-sdk/pull/12154) Add `baseAccountGetter` to avoid invalid account error when create vesting account.
 * (x/authz) [#12184](https://github.com/cosmos/cosmos-sdk/pull/12184) Fix MsgExec not verifying the validity of nested messages.
 * (x/crisis) [#12208](https://github.com/cosmos/cosmos-sdk/pull/12208) Fix progress index of crisis invariant assertion logs.
+* (types) [#12229](https://github.com/cosmos/cosmos-sdk/pull/12229) Increase sdk.Dec maxApproxRootIterations to 300
 
 ## [v0.46.0-rc1](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.46.0-rc1) - 2022-05-23
 

types/decimal.go

@@ -34,7 +34,7 @@ const (
 	maxDecBitLen = MaxBitLen + decimalTruncateBits
 
 	// max number of iterations in ApproxRoot function
-	maxApproxRootIterations = 100
+	maxApproxRootIterations = 300
 )
 
 var (

types/decimal_test.go

@@ -433,11 +433,12 @@ func (s *decimalTestSuite) TestApproxRoot() {
 		{sdk.SmallestDec(), 2, sdk.NewDecWithPrec(1, 9)},                                       // 1e-18 ^ (0.5) => 1e-9
 		{sdk.SmallestDec(), 3, sdk.MustNewDecFromStr("0.000000999999999997")},                  // 1e-18 ^ (1/3) => 1e-6
 		{sdk.NewDecWithPrec(1, 8), 3, sdk.MustNewDecFromStr("0.002154434690031900")},           // 1e-8 ^ (1/3) ≈ 0.00215443469
+		{sdk.MustNewDecFromStr("9000002314687921634000000000000000000021394871242000000000000000"), 2, sdk.MustNewDecFromStr("94868342004527103646332858502867.899477053226766107")},
 	}
 
 	// In the case of 1e-8 ^ (1/3), the result repeats every 5 iterations starting from iteration 24
 	// (i.e. 24, 29, 34, ... give the same result) and never converges enough. The maximum number of
-	// iterations (100) causes the result at iteration 100 to be returned, regardless of convergence.
+	// iterations (300) causes the result at iteration 300 to be returned, regardless of convergence.
 
 	for i, tc := range testCases {
 		res, err := tc.input.ApproxRoot(tc.root)