fix: Crash bcake migration page with unsupported chain (#10726)

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---

## PR-Codex overview
This PR refactors the `PosManagerMigrationFarmTable` component in
`PositionManagerTable.tsx`, optimizing the logic for generating the rows
and simplifying the handling of onStake and onUnStake functions.

### Detailed summary
- Introduced `noop` from `lodash` for `onStake` and `onUnStake`
functions.
- Changed the logic for generating `needToMigrateList` to use optional
chaining and a default empty array.
- Updated the `rows` mapping to directly return objects with structured
data.
- Removed conditional rendering based on `columnSchema` for the row
mapping.

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your
question}`

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apps/web/src/views/Migration/components/bCake/PositionManagerTable.tsx

@@ -5,6 +5,7 @@ import { Flex, Spinner } from '@pancakeswap/uikit'
 import useActiveWeb3React from 'hooks/useActiveWeb3React'
 import React, { useMemo } from 'react'
 import { styled } from 'styled-components'
+import noop from 'lodash/noop'
 import EmptyText from '../MigrationTable/EmptyText'
 import TableStyle from '../MigrationTable/StyledTable'
 import TableHeader from '../MigrationTable/TableHeader'
@@ -41,15 +42,15 @@ export const PosManagerMigrationFarmTable: React.FC<React.PropsWithChildren<ITab
   const { t } = useTranslation()
   const { chainId } = useActiveWeb3React()
 
-  const needToMigrateList: VaultConfig[] = useMemo(() => {
-    if (!chainId) return []
-    return VAULTS_CONFIG_BY_CHAIN[chainId].filter(
-      (vault) => vault.address && vault?.bCakeWrapperAddress && vault?.bCakeWrapperAddress !== vault.address,
-    )
-  }, [chainId])
+  const rows = useMemo(() => {
+    if (!chainId || columnSchema !== V3Step1DesktopColumnSchema) return []
 
-  const rows = needToMigrateList.map((d) => {
-    return {
+    const needToMigrateList: VaultConfig[] =
+      VAULTS_CONFIG_BY_CHAIN[chainId]?.filter(
+        (vault) => vault.address && vault?.bCakeWrapperAddress && vault?.bCakeWrapperAddress !== vault.address,
+      ) ?? []
+
+    return needToMigrateList.map((d) => ({
       id: d.id,
       data: {
         token: d.currencyA.wrapped,
@@ -61,10 +62,10 @@ export const PosManagerMigrationFarmTable: React.FC<React.PropsWithChildren<ITab
         bCakeWrapperAddress: d.bCakeWrapperAddress ?? '0x',
         earningToken: d.earningToken.wrapped,
       },
-      onStake: () => {},
-      onUnStake: () => {},
-    }
-  })
+      onStake: noop,
+      onUnStake: noop,
+    }))
+  }, [chainId, columnSchema])
 
   return (
     <Container>
@@ -79,12 +80,7 @@ export const PosManagerMigrationFarmTable: React.FC<React.PropsWithChildren<ITab
         {account && userDataReady && rows.length === 0 && <EmptyText text={noStakedFarmText} />}
         {account &&
           userDataReady &&
-          rows.map((d) => {
-            if (columnSchema === V3Step1DesktopColumnSchema) {
-              return <PositionManagerFarmRow step={step} {...d} key={`table-row-${d.id}`} />
-            }
-            return null
-          })}
+          rows.map((d) => <PositionManagerFarmRow step={step} {...d} key={`table-row-${d.id}`} />)}
       </TableStyle>
     </Container>
   )