Remove NUMBER_OF_COLUMNS and MAX_CELLS_IN_EXTENDED_MATRIX configuration. (#16073)

**What type of PR is this?**
Other

**What does this PR do? Why is it needed?**
This pull request removes `NUMBER_OF_COLUMNS` and
`MAX_CELLS_IN_EXTENDED_MATRIX` configuration.

**Other notes for review**
Please read commit by commit, with commit messages.

**Acknowledgements**
- [x] I have read
[CONTRIBUTING.md](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md).
- [x] I have included a uniquely named [changelog fragment
file](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md#maintaining-changelogmd).
- [x] I have added a description to this PR with sufficient context for
reviewers to understand this PR.

beacon-chain/sync/initial-sync/blocks_fetcher_test.go

@@ -1366,8 +1366,8 @@ func TestFetchSidecars(t *testing.T) {
 	})
 
 	t.Run("Nominal", func(t *testing.T) {
+		const numberOfColumns = uint64(fieldparams.NumberOfColumns)
 		cfg := params.BeaconConfig()
-		numberOfColumns := cfg.NumberOfColumns
 		samplesPerSlot := cfg.SamplesPerSlot
 
 		// Define "now" to be one epoch after genesis time + retention period.