srht builds: Switch to pexpect

Alpine uses pip, also needs an explicit "python3" now.

FreeBSD requires an explicit "py37" apparently. Blergh.

.builds/alpine.yml

@@ -4,12 +4,13 @@ packages:
   - ninja
   - ncurses-dev
   - pcre2-dev
-  - expect
-  - python
+  - python3
+  - py-pip
 sources:
   - https://git.sr.ht/~faho/fish
 tasks:
   - build: |
+          pip3 install pexpect
           cd fish
           mkdir build || :
           cd build

.builds/arch.yml

@@ -2,8 +2,8 @@ image: archlinux
 packages:
   - cmake
   - ninja
-  - expect
   - python
+  - python-pexpect
 sources:
   - https://git.sr.ht/~faho/fish
 tasks:

.builds/freebsd.yml

@@ -3,11 +3,11 @@ packages:
   - ncurses
   - gcc
   - gettext
-  - expect
   - cmake
   - gmake
   - pcre2
   - python
+  - py37-pexpect
 sources:
   - https://git.sr.ht/~faho/fish
 tasks: