fix(ci)_: lock Go at 1.20 and Alpine at 3.18

Otherwise builds fail with:
```
sqlite3.c:37493:42: error: 'pread64' undeclared here (not in a function); did you mean 'pread'?
37493 |   { "pread64",      (sqlite3_syscall_ptr)pread64,    0  },
      |                                          ^~~~~~~
      |                                          pread
sqlite3.c:37511:42: error: 'pwrite64' undeclared here (not in a function); did you mean 'pwrite'?
37511 |   { "pwrite64",     (sqlite3_syscall_ptr)pwrite64,   0  },
      |                                          ^~~~~~~~
      |                                          pwrite
sqlite3.c: In function 'seekAndRead':
sqlite3.c:37497:49: error: unknown type name 'off64_t'; did you mean 'off_t'?
37497 | #define osPread64 ((ssize_t(*)(int,void*,size_t,off64_t))aSyscall[10].pCurrent)
      |                                                 ^~~~~~~
```

Signed-off-by: Jakub Sokołowski <jakub@status.im>

.dockerignore

@@ -4,4 +4,6 @@
 build/bin
 statusd-data
 wnode-data
+_assets/ci
+_assets/build
 **/*.test

_assets/build/Dockerfile

@@ -1,5 +1,6 @@
 # Build status-go in a Go builder container
-FROM golang:1.19-alpine as builder
+FROM golang:1.20-alpine3.18 as builder
+
 
 RUN apk add --no-cache make gcc g++ musl-dev linux-headers
 
@@ -13,7 +14,7 @@ ADD . .
 RUN make $build_target BUILD_TAGS="$build_tags" BUILD_FLAGS="$build_flags" SHELL="/bin/sh"
 
 # Copy the binary to the second image
-FROM alpine:latest
+FROM alpine:3.18
 
 ARG build_target=statusgo