docs: fix typos in dev documents

these typos were identified by codespell.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#18871

docs/dev/maintainer.md

@@ -178,7 +178,7 @@ latest submodules.
     commit log editor for every submodule to show that commits are being
     updated.
  3. Edit the submodule update commits with any necessary additional
-    imformation. For example, amend the message with `Fixes` tags.
+    information. For example, amend the message with `Fixes` tags.
  4. Use `git push` to publish your work.
 
 By default refresh-submodules.sh will refresh all submodules from their

docs/dev/redis.md

@@ -323,7 +323,7 @@ For the same reason as RMW command, the transaction is not supported
 currently.
 
 > In fact, some commands (e.g. MSET of STRINGs) are also not supported,
-> which also need the transcation mechanism.
+> which also need the transaction mechanism.
 
 ### 5.4 Time to Live (TTL)
 

docs/dev/testing.md

@@ -298,7 +298,7 @@ Jenkins in event of test failure.
 ## Stability
 
 Testing is hard. Testing ScyllaDB is even harder, but we strive to ensure our testing
-suite is as solid as possible. The first step is contribuing a stable (read: non-flaky) test.
+suite is as solid as possible. The first step is contributing a stable (read: non-flaky) test.
 To do so, when developing tests, please run them (1) in debug mode and (2) 100 times in a row (using `--repeat 100`),
 and see that they pass successfully.