Revert some null-safety changes

This commit reverts some null-safety changes which make sense
on main but are too impactful for 6.1.x for Kotlin developers
using -Xjsr305=strict.

See spring-projectsgh-32475

Author: sdeleuze

Diff for: spring-jdbc/src/main/java/org/springframework/jdbc/core/JdbcTemplate.java

@@ -907,13 +907,11 @@ public <T> T queryForObject(String sql, Object[] args, int[] argTypes, Class<T>
 
 	@Deprecated
 	@Override
-	@Nullable
 	public <T> T queryForObject(String sql, @Nullable Object[] args, Class<T> requiredType) throws DataAccessException {
 		return queryForObject(sql, args, getSingleColumnRowMapper(requiredType));
 	}
 
 	@Override
-	@Nullable
 	public <T> T queryForObject(String sql, Class<T> requiredType, @Nullable Object... args) throws DataAccessException {
 		return queryForObject(sql, args, getSingleColumnRowMapper(requiredType));
 	}

Diff for: spring-web/src/main/java/org/springframework/web/context/request/ServletRequestAttributes.java

@@ -143,7 +143,6 @@ private HttpSession obtainSession() {
 
 
 	@Override
-	@Nullable
 	public Object getAttribute(String name, int scope) {
 		if (scope == SCOPE_REQUEST) {
 			if (!isRequestActive()) {
@@ -243,7 +242,6 @@ public void registerDestructionCallback(String name, Runnable callback, int scop
 	}
 
 	@Override
-	@Nullable
 	public Object resolveReference(String key) {
 		if (REFERENCE_REQUEST.equals(key)) {
 			return this.request;

Diff for: spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java

@@ -98,19 +98,16 @@ public Object getNativeRequest() {
 	}
 
 	@Override
-	@Nullable
 	public Object getNativeResponse() {
 		return getResponse();
 	}
 
 	@Override
-	@Nullable
 	public <T> T getNativeRequest(@Nullable Class<T> requiredType) {
 		return WebUtils.getNativeRequest(getRequest(), requiredType);
 	}
 
 	@Override
-	@Nullable
 	public <T> T getNativeResponse(@Nullable Class<T> requiredType) {
 		HttpServletResponse response = getResponse();
 		return (response != null ? WebUtils.getNativeResponse(response, requiredType) : null);

Diff for: spring-web/src/main/java/org/springframework/web/filter/ForwardedHeaderFilter.java

@@ -340,7 +340,6 @@ public int getRemotePort() {
 
 		@SuppressWarnings("DataFlowIssue")
 		@Override
-		@Nullable
 		public Object getAttribute(String name) {
 			if (name.equals(WebUtils.ERROR_REQUEST_URI_ATTRIBUTE)) {
 				return this.forwardedPrefixExtractor.getErrorRequestUri();

Diff for: spring-web/src/main/java/org/springframework/web/multipart/MultipartFileResource.java

@@ -65,7 +65,6 @@ public long contentLength() {
 	}
 
 	@Override
-	@Nullable
 	public String getFilename() {
 		return this.multipartFile.getOriginalFilename();
 	}

Diff for: spring-web/src/main/java/org/springframework/web/multipart/support/DefaultMultipartHttpServletRequest.java

@@ -169,7 +169,6 @@ protected final void setMultipartParameters(Map<String, String[]> multipartParam
 	 * lazily initializing it if necessary.
 	 * @see #initializeMultipart()
 	 */
-	@SuppressWarnings("NullAway")
 	protected Map<String, String[]> getMultipartParameters() {
 		if (this.multipartParameters == null) {
 			initializeMultipart();
@@ -190,7 +189,6 @@ protected final void setMultipartParameterContentTypes(Map<String, String> multi
 	 * lazily initializing it if necessary.
 	 * @see #initializeMultipart()
 	 */
-	@SuppressWarnings("NullAway")
 	protected Map<String, String> getMultipartParameterContentTypes() {
 		if (this.multipartParameterContentTypes == null) {
 			initializeMultipart();