remove unused --config options from commands which don't use it

[asottile]

diff from the help:

diff --git a/before/_base b/after/_base
index d11959d..d8519ec 100644
--- a/before/_base
+++ b/after/_base
@@ -1,9 +1,9 @@
 usage: pre-commit [-h] [-V]
-                  {autoupdate,clean,hook-impl,gc,init-templatedir,install,install-hooks,migrate-config,run,sample-config,try-repo,uninstall,validate-config,validate-manifest,help}
+                  {autoupdate,clean,gc,init-templatedir,install,install-hooks,migrate-config,run,sample-config,try-repo,uninstall,validate-config,validate-manifest,help,hook-impl}
                   ...
 
 positional arguments:
-  {autoupdate,clean,hook-impl,gc,init-templatedir,install,install-hooks,migrate-config,run,sample-config,try-repo,uninstall,validate-config,validate-manifest,help}
+  {autoupdate,clean,gc,init-templatedir,install,install-hooks,migrate-config,run,sample-config,try-repo,uninstall,validate-config,validate-manifest,help,hook-impl}
     autoupdate          Auto-update pre-commit config to the latest repos'
                         versions.
     clean               Clean out pre-commit files.
diff --git a/before/clean b/after/clean
index 9caeeb2..9cfa4d1 100644
--- a/before/clean
+++ b/after/clean
@@ -1,8 +1,6 @@
-usage: pre-commit clean [-h] [--color {auto,always,never}] [-c CONFIG]
+usage: pre-commit clean [-h] [--color {auto,always,never}]
 
 optional arguments:
   -h, --help            show this help message and exit
   --color {auto,always,never}
                         Whether to use color in output. Defaults to `auto`.
-  -c CONFIG, --config CONFIG
-                        Path to alternate config file
diff --git a/before/gc b/after/gc
index b227ce7..97baa66 100644
--- a/before/gc
+++ b/after/gc
@@ -1,8 +1,6 @@
-usage: pre-commit gc [-h] [--color {auto,always,never}] [-c CONFIG]
+usage: pre-commit gc [-h] [--color {auto,always,never}]
 
 optional arguments:
   -h, --help            show this help message and exit
   --color {auto,always,never}
                         Whether to use color in output. Defaults to `auto`.
-  -c CONFIG, --config CONFIG
-                        Path to alternate config file
diff --git a/before/sample-config b/after/sample-config
index 69c67ae..1de26a9 100644
--- a/before/sample-config
+++ b/after/sample-config
@@ -1,8 +1,6 @@
-usage: pre-commit sample-config [-h] [--color {auto,always,never}] [-c CONFIG]
+usage: pre-commit sample-config [-h] [--color {auto,always,never}]
 
 optional arguments:
   -h, --help            show this help message and exit
   --color {auto,always,never}
                         Whether to use color in output. Defaults to `auto`.
-  -c CONFIG, --config CONFIG
-                        Path to alternate config file
diff --git a/before/validate-config b/after/validate-config
index 73bdcfc..2927105 100644
--- a/before/validate-config
+++ b/after/validate-config
@@ -1,5 +1,4 @@
 usage: pre-commit validate-config [-h] [--color {auto,always,never}]
-                                  [-c CONFIG]
                                   [filenames [filenames ...]]
 
 positional arguments:
@@ -9,5 +8,3 @@ optional arguments:
   -h, --help            show this help message and exit
   --color {auto,always,never}
                         Whether to use color in output. Defaults to `auto`.
-  -c CONFIG, --config CONFIG
-                        Path to alternate config file
diff --git a/before/validate-manifest b/after/validate-manifest
index f809370..fd74557 100644
--- a/before/validate-manifest
+++ b/after/validate-manifest
@@ -1,5 +1,4 @@
 usage: pre-commit validate-manifest [-h] [--color {auto,always,never}]
-                                    [-c CONFIG]
                                     [filenames [filenames ...]]
 
 positional arguments:
@@ -9,5 +8,3 @@ optional arguments:
   -h, --help            show this help message and exit
   --color {auto,always,never}
                         Whether to use color in output. Defaults to `auto`.
-  -c CONFIG, --config CONFIG
-                        Path to alternate config file