fix: require thresholds to always be a set majority (#4314)

### Description

- Thresholds must always be a set majority, enforced by a unit test
- Updates thresholds for some chains that should've been updated as the
set expanded

### Drive-by changes

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Are there any minor or drive-by changes also included?
-->

### Related issues

<!--
- Fixes #[issue number here]
-->

### Backward compatibility

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implications, e.g. changes that would prohibit deploying older commits
using this infra tooling?

Yes/No
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### Testing

<!--
What kind of testing have these changes undergone?

None/Manual/Unit Tests
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typescript/sdk/src/consts/multisigIsm.test.ts

@@ -0,0 +1,17 @@
+import { expect } from 'chai';
+
+import { defaultMultisigConfigs } from './multisigIsm.js';
+
+describe('MultisigIsm', () => {
+  describe('defaultMultisigConfigs', () => {
+    it('has thresholds that require a set majority', async () => {
+      for (const [chain, config] of Object.entries(defaultMultisigConfigs)) {
+        const minimumThreshold = Math.floor(config.validators.length / 2) + 1;
+        expect(config.threshold).to.be.greaterThanOrEqual(
+          minimumThreshold,
+          `Threshold for ${chain} is too low, expected at least ${minimumThreshold}, got ${config.threshold}`,
+        );
+      }
+    });
+  });
+});

typescript/sdk/src/consts/multisigIsm.ts

@@ -47,7 +47,7 @@ export const defaultMultisigConfigs: ChainMap<MultisigConfig> = {
   },
 
   base: {
-    threshold: 2,
+    threshold: 3,
     validators: [
       '0xb9453d675e0fa3c178a17b4ce1ad5b1a279b3af9',
       '0xb3ac35d3988bca8c2ffd195b1c6bee18536b317b', // staked
@@ -81,7 +81,7 @@ export const defaultMultisigConfigs: ChainMap<MultisigConfig> = {
   },
 
   bsc: {
-    threshold: 2,
+    threshold: 3,
     validators: [
       '0x570af9b7b36568c8877eebba6c6727aa9dab7268',
       '0x8292b1a53907ece0f76af8a50724e9492bcdc8a3', // dsrv
@@ -100,7 +100,7 @@ export const defaultMultisigConfigs: ChainMap<MultisigConfig> = {
   },
 
   celo: {
-    threshold: 2,
+    threshold: 3,
     validators: [
       '0x63478422679303c3e4fc611b771fa4a707ef7f4a',
       '0x622e43baf06ad808ca8399360d9a2d9a1a12688b', // dsrv
@@ -167,7 +167,7 @@ export const defaultMultisigConfigs: ChainMap<MultisigConfig> = {
   },
 
   ethereum: {
-    threshold: 3,
+    threshold: 4,
     validators: [
       '0x03c842db86a6a3e524d4a6615390c1ea8e2b9541',
       '0x94438a7de38d4548ae54df5c6010c4ebc5239eae', // dsrv
@@ -206,7 +206,7 @@ export const defaultMultisigConfigs: ChainMap<MultisigConfig> = {
   },
 
   gnosis: {
-    threshold: 2,
+    threshold: 3,
     validators: [
       '0xd4df66a859585678f2ea8357161d896be19cc1ca',
       '0x19fb7e04a1be6b39b6966a0b0c60b929a93ed672', // dsrv
@@ -308,7 +308,7 @@ export const defaultMultisigConfigs: ChainMap<MultisigConfig> = {
   },
 
   moonbeam: {
-    threshold: 2,
+    threshold: 3,
     validators: [
       '0x2225e2f4e9221049456da93b71d2de41f3b6b2a8',
       '0x645428d198d2e76cbd9c1647f5c80740bb750b97', // dsrv
@@ -331,7 +331,7 @@ export const defaultMultisigConfigs: ChainMap<MultisigConfig> = {
   },
 
   optimism: {
-    threshold: 2,
+    threshold: 3,
     validators: [
       '0x20349eadc6c72e94ce38268b96692b1a5c20de4f',
       '0x5b7d47b76c69740462432f6a5a0ca5005e014157', // dsrv
@@ -357,7 +357,7 @@ export const defaultMultisigConfigs: ChainMap<MultisigConfig> = {
   },
 
   polygon: {
-    threshold: 2,
+    threshold: 3,
     validators: [
       '0x12ecb319c7f4e8ac5eb5226662aeb8528c5cefac',
       '0x008f24cbb1cc30ad0f19f2516ca75730e37efb5f', // dsrv
@@ -404,7 +404,7 @@ export const defaultMultisigConfigs: ChainMap<MultisigConfig> = {
   },
 
   scroll: {
-    threshold: 2,
+    threshold: 3,
     validators: [
       '0xad557170a9f2f21c35e03de07cb30dcbcc3dff63',
       '0xb3ac35d3988bca8c2ffd195b1c6bee18536b317b', // staked