go: bumped minimum required version 1.16

Due to github.com/daixiang0/gci requiring io/fs, the minimum required
Go version for aerc needs to be bumped to 1.16

Signed-off-by: Moritz Poldrack <git@moritz.sh>
Signed-off-by: Robin Jarry <robin@jarry.cc>

.builds/alpine-edge.yml

@@ -25,8 +25,8 @@ tasks:
       cd aerc
       go test ./...
   - ancient-go-version: |
-      curl -O https://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/go-1.13.13-r0.apk
+      curl -O https://dl-cdn.alpinelinux.org/alpine/v3.14/community/x86_64/go-1.16.15-r0.apk
-      sudo apk add ./go-1.13.13-r0.apk
+      sudo apk add ./go-1.16.15-r0.apk
       cd aerc
       make clean
       make

CHANGELOG.md

@@ -29,6 +29,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Background mail count polling when the default folder is empty on startup.
 - Wide character handling in the message list.
 
+### Deprecated
+
+- Support for go < 1.16.
+
 ## [0.11.0](https://git.sr.ht/~rjarry/aerc/refs/0.11.0) - 2022-07-11
 
 ### Added

README.md

@@ -64,7 +64,9 @@ And likely other platforms.
 
 Install the dependencies:
 
-- go (>=1.13)
+- go (>=1.16) *(Go versions are supported until their end-of-life; support for
+  older versions may be dropped at any time due to incompatibilities or newer
+  required language features.)*
 - [scdoc](https://git.sr.ht/~sircmpwn/scdoc)
 
 Then compile aerc:

go.mod

@@ -1,6 +1,6 @@
 module git.sr.ht/~rjarry/aerc
 
-go 1.13
+go 1.16
 
 require (
 	git.sr.ht/~sircmpwn/getopt v1.0.0