maint: ignore all .a files in .gitignore

* .gitignore: Rather than add the new src/libcksum_pclmul.a,
just ignore any such libs.
* src/.gitignore: Likewise.
Reported by Kristoffer Brånemyr.

.gitignore

@@ -4,6 +4,7 @@
 *.gcda
 *.gcno
 *.o
+*.a
 *~
 ._bootmp
 .deps
@@ -71,7 +72,6 @@
 /lib/iconv_open-zos.h
 /lib/inttypes.h
 /lib/langinfo.h
-/lib/libcoreutils.a
 /lib/limits.h
 /lib/link-warning.h
 /lib/locale.h
@@ -181,7 +181,6 @@
 /src/fs-kernel-magic
 /src/fs-latest-magic.h
 /src/fs-magic
-/src/libsinglebin_*.a
 /src/make-prime-list
 /src/primes.h
 /src/single-binary.mk

src/.gitignore

@@ -47,7 +47,6 @@ id
 join
 kill
 libstdbuf.so
-libver.a
 link
 ln
 localedir.h