Use jq's IN() instead of index()

The end result is the same, but the construction is more ergonomic.

Dockerfile-linux.template

@@ -103,7 +103,7 @@ RUN set -eux; \
 		"$APACHE_LOCK_DIR" \
 		"$APACHE_RUN_DIR" \
 		"$APACHE_LOG_DIR" \
-{{ if [ "bullseye" ] | index(env.suite) then "" else ( -}}
+{{ if env.suite == "bullseye" then "" else ( -}}
 # https://salsa.debian.org/apache-team/apache2/-/commit/b97ca8714890ead1ba6c095699dde752e8433205
 		"$APACHE_RUN_DIR/socks" \
 {{ ) end -}}
@@ -326,7 +326,7 @@ RUN set -eux; \
 # https://github.com/docker-library/php/issues/822
 		--with-pic \
 		\
-{{ if [ "8.1" ] | index(env.version | rtrimstr("-rc")) then ( -}}
+{{ if env.version | rtrimstr("-rc") == "8.1" then ( -}}
 # --enable-ftp is included here for compatibility with existing versions. ftp_ssl_connect() needed ftp to be compiled statically before PHP 7.0 (see https://github.com/docker-library/php/issues/236).
 		--enable-ftp \
 {{ ) else "" end -}}
@@ -348,7 +348,7 @@ RUN set -eux; \
 		--with-readline \
 		--with-zlib \
 		\
-{{ if [ "cli", "zts" ] | index(env.variant) then ( -}}
+{{ if env.variant | IN("cli", "zts") then ( -}}
 # https://github.com/docker-library/php/pull/1259
 		--enable-phpdbg \
 		--enable-phpdbg-readline \
@@ -360,7 +360,7 @@ RUN set -eux; \
 # in PHP 7.4+, the pecl/pear installers are officially deprecated (requiring an explicit "--with-pear")
 		--with-pear \
 		\
-{{ if [ "8.1", "8.2" ] | index(env.version | rtrimstr("-rc")) then ( -}}
+{{ if env.version | rtrimstr("-rc") | IN("8.1", "8.2") then ( -}}
 # bundled pcre does not support JIT on riscv64 until 10.41 (php 8.3+)
 # https://github.com/PCRE2Project/pcre2/commits/pcre2-10.41/src/sljit/sljitNativeRISCV_64.c
 # https://github.com/php/php-src/tree/php-8.3.0/ext/pcre/pcre2lib
@@ -374,7 +374,7 @@ RUN set -eux; \
 		--with-libdir="lib/$debMultiarch" \
 {{ ) end -}}
 {{ # https://github.com/docker-library/php/issues/280 -}}
-{{ if [ "cli", "zts" ] | index(env.variant) then "" else ( -}}
+{{ if env.variant | IN("cli", "zts") then "" else ( -}}
 		\
 		--disable-cgi \
 {{ ) end -}}
@@ -397,7 +397,7 @@ RUN set -eux; \
 		--enable-zts \
 # https://externals.io/message/118859
 		--disable-zend-signals \
-{{ if [ "8.1", "8.2" ] | index(env.version | rtrimstr("-rc")) then ( -}}
+{{ if env.version | rtrimstr("-rc") | IN("8.1", "8.2") then ( -}}
 		--enable-zend-max-execution-timers \
 {{ ) else "" end -}}
 {{ ) else "" end -}}