feat(preset)!: decrease prConcurrentLimit to 10 (#12892)

BREAKING CHANGE: Configurations extending config:base will now default to maximum 10 concurrent PRs instead of 20.

docs/usage/configuration-options.md

@@ -243,7 +243,7 @@ Configuring this to `true` means that Renovate will detect and apply the default
 ## branchConcurrentLimit
 
 By default, Renovate won't enforce any concurrent branch limits.
-The `config:base` preset that many extend from limits the amount of concurrent branches to 20, but in most cases we would recommend lower values such as 5 or 10.
+The `config:base` preset that many extend from limits the amount of concurrent branches to 10, but in many cases a limit as low as 3 or 5 can be most efficient for a repository.
 
 If you want the same limit for both concurrent branches and concurrent PRs, then just set a value for `prConcurrentLimit` and it will be reused for branch calculations too.
 However, if you want to allow more concurrent branches than concurrent PRs, you can configure both values (e.g. `branchConcurrentLimit=5` and `prConcurrentLimit=3`).

lib/config/presets/index.spec.ts

@@ -615,7 +615,7 @@ describe('config/presets/index', () => {
           ':ignoreModulesAndTests',
           ':autodetectPinVersions',
           ':prHourlyLimit2',
-          ':prConcurrentLimit20',
+          ':prConcurrentLimit10',
           'group:monorepos',
           'group:recommended',
           'workarounds:all',

lib/config/presets/internal/config.ts

@@ -9,7 +9,7 @@ export const presets: Record<string, Preset> = {
       ':ignoreModulesAndTests',
       ':autodetectPinVersions',
       ':prHourlyLimit2',
-      ':prConcurrentLimit20',
+      ':prConcurrentLimit10',
       'group:monorepos',
       'group:recommended',
       'workarounds:all',